Pattern Review ran a contest in May to knock off RTW garments; I didn't get to participate in that contest, but there are some really striking entries. Voting is open now to choose the winner...even if you don't vote (and if you're a PR member, you really should...), have a look at the entries:
RTW Knockoff Contest
It says at the top of the page there are 25 participants...but that's just the number of folks who signed up. There are actually only 13 entries; you need to read the reviews to find photos of the original garments the reviewers are knocking off. There's some excellent work there, and it was hard to vote for just one.
Go be inspired! ;)