Well theirs actual a bunch of LAN hacks.
The most "trusted" so far (in my view) is StarFriends Lan Hack.
Its also the one that supports the statement :
"As soon as Blizzard gives LAN the project is instantly obliterated"
A good Launcher and HowTo can be found here:
directed from: (Read stuff about it first before trying on your own, also linked here in the forum)
However, its not a "perfect" solution ; just kick Blizzard in the nuts for taking the feature away ; worst idea ever ...