I don't like Twitter or Tumblr, but I think Polyvore has the potential to be a really good mix of the two. There's so much creativity on here and, unlike Tumblr, it's all very centered and everyone's got their own portfolio, instead of just 'inspiration' they lazily dumped on their page. I'm going to start throwing things at my profile and seeing where it goes from there.It's like Twitter for design fanatics, how great is this?!