http://confessionsofafabricaddict.blogspot.com/p/whoop-whoop-fridays.html. She's very forgiving to those who don't know their Fridays from their Saturdays.
If you love color and are interested in a color challenge, go here: http://3creativestudios.com/blog. On the 16th of every month, they announce a color palette, drawn from a photo. You make something creative, using one or all of the colors. No sign-up or requirements, but you can add your project to their Flickr page, or just see what others have made. My challenge to myself was to use the monthly color palette for a BOM that is itty bitty paper piecing that finishes out to about 3" x 4". The pp blocks are monthly themes, and I've been able to use the colors from the first three months for a Christmas tree, an iris, and now the watermelon. By process of elimination, I'm worried the snowman block will be the last one to be made, and the last color palette will be orange and green! Here is this month's gorgeous palette, just to whet your appetite: http://3creativestudios.com/blog/2011/04/15/color-palette-challenge-april/
The same blog has a monthly technique and journal quilts sections, see the links on the right side of their blog. For you artsy people, you'll find lots of eye candy, and maybe something challenging, as well!