Here’s a button I’ve made:
Not too inspiring, is it? I really wanted to make myself a Simpsons avatar, but it got too time-consuming.
(If anybody’s interested, I’m not actually a Linux Dork — I only have pretensions to be one.)
As I see it, the image-generators or the images themselves don’t have a bunch of educational value, and my intellect doesn’t feel enhanced by playing with them. However, they make nice additions to web content and can make your product more enticing.