Polyvore - Fashion freaks rejoice, you're a part of the web too (lostthetech.com)

Polyvore impressed when they launched a while back because they have a very simple, clean and functional interface.

Actually their functions weren't and still aren't as advanced as other online scrapbook / graphic sites, but their UI has let them grow to be very popular...

I guess a good lesson for rest of us newbies out there building consumer web apps.