Ever since I found out you can dye yarn with kool-aid, I have been wanting to try it.  And I will...one day...maybe over the summer or by next year.  But knowing how I am, of course I have to go looking to see tutorials.

http://www.knitty.com/ISSUEspring07/FEATdyeyourown.html - with acid based dyes
http://naturalsuburbia.blogspot.com/2010/01/how-to-dye-yarn-with-sun-dye.html - with food colouring