I randomly entered my birthday date on FA as number in the URL to see if there's a picture behind that number. And there is! *g* This could almost be a meme.

My birthday is September 2, 1979 - so here's "my" link: ;)
http://www.furaffinity.net/view/9279

Of course you can write the number in different ways, according to your country (DDMMYY, MMDDYY, YYMMDD...).
So what's your "FA birthday picture"? ;)