The locally developed Half-Life 2 modification Dystopia has officially hit version 1.0 today. Their website is pwned with traffic, but for those who came in late:

Dystopia places the player into tense combat situations in a high tech world spanned by computer networks. As either Punk Mercenaries or Corporate Security Forces the player will fight through the physical world to gain access, via jack-in terminals, to cyberspace.

Download ahoy locally from AusGamers. You'll find local servers all over the shop.