morningstar4 did this, and I quite liked her approach to it, so I've decided to do it this way too.
Look at your LJ userpics list. If you have fewer than 50 icons, pick every fifth one. If you have between fifty and seventy-five icons, pick every seventh one. If you have over seventy-five icons, pick every tenth one. If you have fewer than ten, pick all of 'em. List them on your LJ and tell everyone exactly why you have it, why it's interesting to you, and what significance it has. But like D, instead of going every tenth, I picked one icon out of every ten that I thought perhaps people might not understand. So here are my twelve icon explanations; if you'd like a different one explained, leave a comment and let me know which one has you curious.
( Oi! Down here! )