Andrew_Carter whered you get your new avatar, man? That picture was so sick (crazy) to begin with and now its even better! Is it just photoshopped or is that more like a characterature?
It was drawn by Kayote (Greg) in this thread: http://www.unicyclist.com/forums/showthread.php?s=&threadid=36557&perpage=20&highlight=art&pagenumber=2
Thanks Kacey. I really did a search on this before i posted but i guess my search wasnt good enough.
I’m gonna go sulk now. 
It really is an amazing drawing isn’t it! Thanks Greg!
To get it like it is I used The GIMP (free image editing program). As per Daniel’s (daino’s) advice I added another ‘Alpha Layer’ in the Layers window thing and then removed the background with the little magic wand tool and saved it as a .gif. The important thing I discovered was to resize the image before removing the background. That way the boundaries of the image wiill be slightly ‘furry’ rather than sharp and horrible.
Andrew