Let me get this straight. You want to find a site that depicts people becoming old very fast? To each his own, but that's an odd fetish. I prefer watching a girl becoming a busty 25 year-old quickly. Oh, well, I'm sure there's something like that out there. Good look.
Oh, have you seen Howl's Moving Castle? Good movie with a young woman who is cursed and becomes an old lady. There are a few scenes where she seems to get younger again for a few moments again and then older again, back and forth. These later changes she doesn't notice and it's subtle.
Oh, and have you tried the visible time site?
http://www.geocities.com/visible_time/index.htm
Also check the ar archive's link page:
http://www.ararchive.com/component/o...,17/Itemid,18/