This is from the pixiv staff.

Starting today July 11, 2011 (Monday), 「Quarterly pixiv vol.06」 will be holding an illustration contest.
Best works that are selected will be published in the upcoming 「Quarterly pixiv vol.06」 issue.

Contest details are as follows
Please make sure you have read the following application requirements for Free theme section / Yukata and Japanese clothes section / Ano Hana section before joining.

【Holding Period】
July 11 (Mon) ~ 23:59, August 8 (Mon)
※Ano Hana section will instead end at August 11 (Thu).

【Participating Method】
(1) We will be collecting illustrations based on the following 3 themes :
1. Free theme section
For this contest, you are free to submit any illustration as long as it is original theme.

2. Yukata & Japanese clothes section
Japanese clothes and yukata that plays an active role in many fireworks and festivals.
We are looking foward to your artworks that illustrates this wonderful season.  

3. Ano Hana section
Let draw illustations with the recently broadcasted big hit emotionally moving anime, “Ano no Hi Mita Hana no Namae wo Bokutachi wa Mada Shiranai” (We Still Don’t Know the Name of the Flower We Saw That Day) as the theme!

(2) Please choose any relevant tags below and attach it to your submission in order to enter this contest in pixiv.

For Free theme section : Qpixiv6フリー
　>>Article on this tag
For Yukata and Japanese Clothes section : Qpixiv6浴衣＆和服
　>>Article on this tag
For Ano Hana section : Qpixiv6あの花
　>>Article on this tag

※ Any submission that does not include any of the following tags from above will not be counted.

◆Participation Requirements （Free theme section）
◆Project Index
◆List of Submitted Works

◆Participation Requirements （Yukata and Japanese clothes section）
◆Project Index
◆List of Submitted Works

◆Participation Requirements （Ano Hana section)
◆Project Index
◆List of Submitted Works

◆『Ano no Hi Mita Hana no Namae wo Bokutachi wa Mada Shiranai.』 Official Homepage
◆Official twitter