[Thinkpad] Least expensive thinkpad out there with GOOD built in wireless?

[Courtney Hook]

 My old 760XL is just too poor a performer these days when it comes to 
wireless. I sit and wait, and wait , and wait - - - , *sigh*. My son-in-law 
comes over and sits beside me at the kitchen table with his new Compaq 
Presario dual processor with built in wireless, and proceeds to surf merrily 
away as if it wasn't even a wireless network. It's THAT good on my old "B" 
netgear router. Jerk. :-)
So I love the size of my little notebook compared to his laptop, but I NEED 
that performance of surfing. What is out there that would fit the bill 
without breaking my bank? I can go to Bestbuy and get his computer for 600 
bucks, but I love the size of my old 760xl. Would LOVE some input.
Thanks,
Courtney