Necklace Net code

I'm chugging along on some network code for necklace. The first release will be about the basic pervasive multiplayer element (i.e. a unified solution database). The next milestone after that is a decent level-sharing mechanism-- not that pasting text to your friends over IM doesn't work or anything.
One reason (among many) that this release has been taking a while is that I'm debating what really constitutes a "similar" level.In the most general sense, it's the graph structure on the pieces and the bitmap of the obstacles -- but I think that finding a canonical form here might well begin to look like graph isomorphism.Not to mention that there is plenty more path to travel here (reflections and rotations of levels are pretty much the same level).Perhaps I should just avoid this slope altogether.