Anti Aliasing doesnt seem to work much

[Killerwatt]

I too only have the off option for in game AA.
Specs:
Antec Nine Hundred Two Case,
Sapphire Radeon HD 4870 Vapor-X 2GB,
Akasa PowerMax 850W Power supply,
Asus P6T Motherboard LGA1 366 Intel X58 ATX RAID SA,
Intel Core i7-920 D0 Step Processor (8M Cache),
Corsair XMS3 3GB (3x1024M B) DDR3 Memory 1600MHz,
Noctua NH-U12P CPU Cooler SE1366,
LG GH22NP20 22x DVDRW/ RAM,
Seagate Barracuda 7200.11 1.5TB Hard Disk Drive 72 (Two),
Windows XP Home Edition. updated to SP3
No overclocking done and everything running at stock speeds