I am looking for a 4 player offline racing game but most games like the Gran Turismo series, Burnout Series and Need for Speed Underground series only handle 2 player offline.  Does anyone know any 4 player racing games?  Do any 4 player non-racing games for the ps2 exist with the exception of carnival games, shrek party, and the like......

I'm not sure about 4 player support, but this list has most of the racing games available on the ps2.

http://videogames.yahoo.com/ps2/racing/

ATV offroad fury 2 (though other ATV offroad games most likely do as well. 2 also has an awesome 4 player hockey minigame)
Downhill Domination (very fun downhill mountain bike racing)

That's all I can think of off the top of my head.

Grand turismo 3 and 4 via lan is all I can remember. I remember GT3 you could hook up 8 players via firewire over a hub/lan. Pretty much all racers can be played that way if you have a router because I hooked up a lan party that had I believe 6 ps2 playing midnight club dub edition and it ran smoothly.

I was thinking more along the line with a multi-tap not a lan connection.

micro machines!

oh! sorry

Well Mashed, a relatively unknown game had fantastic offline multiplayer

However, it is not entirely about racing. Basically, up to 4 of you control your tiny little cars on the same screen, picking up weapons and shooting each other. If you fall behind, you die, but here is the great thing, you then get to target an air strike on your friends left behind. It was a great game for MP, but as I said it is quite obscure

there's always sports games and wrestling games.

Mashed is the best offline multiplayer game in history.