Some nice tweaks are already emerging for HL2. Tweakguides is covering them, from the obvious - reduce sound quality - to giving the heapsize more memory - ‘-heapsize 132000′.
There is a Hl2 multiplayer workaround over at hl2world.com/ as well.
ATI has new beta drivers out that contain HL2 speedups, www.ati.com/support/infobase/4701.html
Niceness.
