I don't know about local area networks specifically, but there are several other games which made be played specifically over the net.
Railracer from http://www.blindadrenaline.com/ most of the games from the vip gameszone (I'd particularly recommend lords of the galaxy and galaxy ranger), found at http://vipgameszone.com/index.php
boppit ultimate from lighttech interactive at http://www.lighttechinteractive.com/webpage/index.php
An as Cx2 says there's audio quake from http://www.agrip.org.uk/ Topspeed2 from http://www.playinginthedark.net/index_e.htm and sound Rts from http://jlpo.free.fr/soundrts
Railracer, Audio quake, Sound rts and topspeed 2 are also playable by four or more players at once in real time, so might be good for multiple friends.
Hth.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)