Quick update after buying a 15m Ethernet cable and running it under the house.
Laptop - 12,000kbps (wireless)
PS3 - 1,500kbps (wireless, in same location as laptop,about 45% strength)
PS3 - 12,000kbps (ethernet hard wired)
Thank god for that.
I can't see the cable so that's fine and it only cost me 18 bucks.
Verdict = PS3 wirless sucks
(and Singstar songs now take < 5mins)