Quoted from 4dawgz (the scanlator)-
"So there's a magazine called Gelatin where various manga artists are given some coloring crayons and then told to draw whatever they want in full color. The plot for this is about a guy and a girl who go on a mission to retrieve a pair of shorts from an island... aaaaand that's it. All you'll find is a nice slice-of-life story and lovely colored pages."

A gag manga following the exploits of a foolish out of work father and a realist daughter trying to get him into a job that will pay for private school.

From Anime Waves:

Tamao loves to draw pictures of RINGO, his fantasy girl, in his sketchbook. But his life changes overnight after he successfully tests his secret VIII Project...Tamao soon discovers that creating a walking, talking, virtual idol is a long and difficult process...

Ringo's life isn't going so well. Her father's company went bankrupt, they have to move to a new town, she's leaving her crush behind and worst of all, she has met weirdo in the new town she's moved to. Will she ever find happiness?

Ruca, trapped under a rock, is saved by a man dragging a large sword along the ground. Coming from Brazil to Niigata, she offers him a drink from a pokan juice. Why does he drag this large sword and how does the earth turning into a vast desert land relate to him?

Raruto is a Spanish webcomic by Jesús García Ferrer (Jesulink), published from 2005 to 2008, and is a parody of the Japanese manga Naruto with absurd humor and a careless super-deformed artstyle. There is a sequel, Raruto Sisepuede, ongoing since 2008. Despite the artwork, Raruto became the most well-known parody of Naruto in Spain, and has been sold in printed volumes in manga conventions in Spain.The popularity of Raruto led Jesulink to start a new manga, "5 Elementos", which despite being also published online, has sold over 15000 copies in its printed format.Sequel:> Raruto Sisepuede(http://mangapark.com/search?q=sp/raruto-sisepuede)

Sugano Ikkei is a typical teenager at his high school and lives with his older brother Hyakkei who is an editor at a publishing company. Hyakkei is in charge of several artists and writers and his job is to support them in anyway possible. However, he broke his leg and is unable to leave the hospital for a week and he has a very important meeting with a very shy writer named Tokito Aona which has taken months to get a face to face meeting. As they look really alike, he asks Ikkei to dress up as him and go as Hyakkei. The meeting goes well without her knowing the truth, but Ikkei is forced to go to another meeting with Fujimaki Misuzu, an artist moving to Tokyo in order to continue working. To his surprise, both girls, Tokito and Fujimaki, are in the same class as he. Now he has to juggle being Hyakkei as an editor to the two girls as well as be their classmates as Ikkei, and do all this without letting out the secret that he is the same person.

On Earth, pouring boiling water over a bowl of instant Ramen means you're hungry. On Planet Cup-Ramen, the women are human sized and the men are three-inch tall. Instant sized men need to be brought up to human size by, you guessed it, pouring hot water on them! It's also a proposal of marriage. Sumire - a lively 16 year old boy, was only hungry when he bought this peculiar looking cup Ramen from the shop. Little did he know that it was actually the space ship of the pint size Prince Kanmen of the Planet Cup-Ramen! Prince Kanmen is very persistent; and Sumire who is caught in between various fiancées, older brothers, younger brothers, obsessive SM handmaidens and pop stars, he may just end up marrying Prince Kanmen out of sheer exhaustion!

From Anime-Source:
Taking a break from her popular, brilliant, Fullmetal Alchemist; Arakawa-sensei drew up a one-chapter humorous shounen story about a Frankenstein tournament, for magazine GX to commemorate their 5th year anniversary.

In a deserted place, wish upon coins, then laugh loudly three times, your wish will come true... The carefree and outgoing Eu Hee secretly likes a girl; however the person she likes is another senpai. If this isn't ridiculous enough Eu Hee decided to help her confess to her crush! A sweet and light-hearted tale, the Mi Sa-Lyn's first oneshot after her Debut.

After a four-year absence, Ishida Kotori (QP) returns to the city where even his face instills fear amongst the locals. Trying desperately to move away from his once violent past and live an honest life, former classmate and now high profile gang member, Azuma Ryou, has other plans for QP's future...

QP: Soul of Violence is written by Takahashi Hiroshi and set within the same universe as his other works, Crows and Worst.

She's the most popular girl in school, but what all the guys don't know about Akari is that she's actually a yaoi-crazed doujinshi artist... and her subjects look an awful lot like some boys from school. from snoopycool

From StarryHeaven:
A short shoujo story about a girl who wants to continue the family tradition of her family…that is, get married at 16 and have a girl child at 17! A very crazy story about a very crazy girl named Ren who falls in love with one of the most popular boys in school, Juuya, at first sight!

From ClubManga:

Kayama Miharu enters her new middle school and immediately becomes friends with Mori Mizutama, a very cute guy she first takes to be a girl but is really a boy. However, though Miharu likes Mizutama, she cannot tell him, especially ever since the older Kawagoe (yes, a boy) seems to have taken Mizutama's interest instead. Miharu tries to be cute for Mizutama, but finds it practically impossible, as he is both more talented at home economics and more cute than herself. Then, Mizutama joins the Kawagoe's soccer club instead of the comedy-lovers' club the two of them had decided on earlier...

Also contains the story Fuyu Hanabi

4-koma manga

One day, an un-named ordinary high school girl (her name is left to your imagination), meets Cheko, a maid sent forth from a village of maids. Cheko the maid can melt, fly, remove her head and violate physics.

Surrounding the "ordinary high school girl" and her strange little maid are yuki-onna's who hate cold, a cute squid that can speak, moe yankees, tsundere maid assasins, ecchi lesbian teachers, trap yuki-otoko's, gentlemanly yakuza and many more.

[From AT-Translations]:

Based on an ero-game, Prism Palette is Peach-Pit’s (famous for DearS, Zombie Loan, Rozen Maiden and assorted other manga) first publication. It follows the main character, Masaki Shirai, as he spends his days at school, surrounded by beautiful girls.

From TJo:
TJO's 8th manga is Suzuki Noritaka's Shikotama, a comedy involving demons and more demons and uh, a little bit of snowboarding.

The sexy demon Mako has been sent from the demon world with an ultimatum mission from her father: bring him the "Supreme Soul," or else! However, getting the "supreme soul" proves to be a lot more problematic than Mako ever imagined as her friends fight back and a group of rival demons show up...

The guy who's always been by my side... the distance between us changes...

She calls herself Sexy Voice. To most of the world, she's just Hayashi Niko, an ordinary schoolgirl - but when time permits, she lives a double life as a hired investigator/spy. To help her, she has recruited the rather unlikely assistant she calls Robo, a geeky lump of a man who doesn't really know why he feels the need to do everything she tells him to. He just does it. Together, the odd team solve a number of cases for Sexy Voice's employer, an aging gangster.

Nanami Sekai gets scammed out of every penny he has, left only with a pair of boxers and a 3,000,000 yen debt. He then meets a girl, Ritori, who offers him a deal that seems too good to be true: she will take care of his debt if he will be her captain and help her with her job.

[Note]
It seems that this manga has been discontinued because the author became incapacitated during serialization and was not able to keep 2 series running.