Bukkit

This is the initial release that I'm comfortable with distributing. It's probably laden with bugs, and there are some important features missing (like a way for players to legitimately craft a portal without an op giving them the wand), but it's been tested a bit on a server and it seems to be working well.

I've added a white-list for entity types we can clone completely for cross-world travel. That way, villagers won't be sent through and lose all their trading details.

I haven't had the opportunity to do any performance testing on large servers yet, and no long term testing for memory leaks and the such has been performed.

There's currently no way for a normal player to get a portal wand, though they can use wands after they've been given them.

Frames aren't limited to any specific material right now, and there's no way to configure frames at all, aside from the overall portal size.