The best hands down is Bailey's take on the trend at Burberry. Simple, clean, slight slouchiness to the sock, not-to-school girl-ish, and HARD! I love it! it looks like a booty from afar, but not quite.
I think it's a great, yet the public is not keen to it, trend. plus you do have to have Karolina Kurkova mile long legs to do it, otherwise you'll look stumpy =P