I’ve started a page with free (public-domain) LiveJournal userpics cropped and resized from pictures I’ve taken. Right now there are only a handful, but I’ll add to them. Feel free to grab and use, for LiveJournal or anything else. (Note that I’m only releasing the cropped, resized 100x100-pixel images into the public domain; the originals are not, although if you want a larger version of one of them drop me a note or comment and I might be happy to accommodate you.)
The userpics are available at http://www.aq.org/~js/clipart/userpics/, or in a less-scrolling-required grid format at http://www.aq.org/~js/clipart/userpics/grid.html.
(By the way, I used to use the gecko picture there as one of my own userpics, but I’ve retired it.)