Check with Dell and IBM (their websites) for reconditioned laptops - they have full warranties, and are often in perfect shape. If someone can't figure out how to turn a computer on and it gets returned, it becomes reconditioned.
I've helped friends buy recon'd dell desktops, usually the only thing wrong was the keyboard (the one part they don't test, I guess), and the cost was 25-50% of new.
Same with IBM - top quality laptops at a discount. Of course, a discounted IBM is still pretty expensive.
But you might find better prices on ebay.com. Just make sure the laptop still has a few years of warranty (manufacterers warranty is better) left on it.
I bought my IBM Thinkpad T40 (a killer laptop BTW) for a very, very good price on ebay (more than $1000 below some of the prices I've seen on the internet and a good $500 below what's on IBM's used site), brand new with 3 years warranty and all.