While reading Bricks Down Under tonight, I came across a new web-based tool that looked very exciting (and a title too good not to copy). Rebrickable, made by Nathan Thom, is a brilliant website which offers a tool where you to enter sets you own, and find sets (and MOCs) you can build. So if there’s been an old set that you’ve always wanted to own, maybe you’ll find you already do.
The website went live early due to a leak so its range of sets is currently limited but it is increasing.
Doesn’t Peeron already offer this function for sets? It doesn’t do MOCs, as far as I know, though.
I think Peeron could tell you what you could build from your whole collection. Not sure you could enter a few sets and see what came out.
Great site, I was attempting something like this non web based, guess I won’t have to now :)