We're totally with you on Mila's dress being a drop-dead stunner--she made our best dressed list in it!--and it would definitely make for a super-glam prom. Companies like eDressme.com and A.B.S. by Allen Schwartz usually make Oscar knockoffs a few weeks after the event, but this dress was so darn unique that it proved too tricky even for the masters of the lookalike (but if you want to look like Natalie Portman, Reese Witherspoon, or Gwyneth Paltrow on the big night, here are their offerings!).

 A Mila-like creation calls for a bit of ingenuity, and I think I've got just the answer. If you're willing to get a bit DIY, I'd start with a fabulous white lace frock and dye it yourself at home! This BCBG number is marked down from $548 to just $274, and with a bottle of RIT dye and a some vision, it could be a very close match.

If that route seems too complicated for you, here are a few gorgeous dresses that don't have the exact same look, but a highly "inspired by" vibe (my favorite is this J. Crew number, at a relatively affordable $175):