Can you swap the cpu just like a desktop unit? (Seems as though that would be reasonable.)
That depends on how the laptop is designed. I do know you CAN replace the P4-
M CPU in a Dell Inspiron 8200.
He's looking at Alienware. What other vendors are there?
Plenty (Dell, Compaq, IBM, Toshiba, HP, Gateway, etc., etc.). Alienware/Sager is at the bottom of my list. I know someone who had a Sager laptop and it was nothing but problems from day 1. I would not buy from them.
He would love one with onboard wireless.
Lots of laptops support WI-FI. Most can use an internal Mini-PCI WI-FI card.
A friend of mine is looking at getting one with a desktop cpu...
Why??? There is NO advantage to getting a desktop CPU over a mobile CPU except for price. I have never heard anything good about desktop CPU's in laptops. A recent review (in PC Games magazine) tested the Dell Inspiron 8200, Alienware, Gateway 600xl, and a Toshiba laptop. The Inspiron 8200 and the Alienware were pretty much tied for first place. IMO that does not look good for the Alienware which had a much faster rated desktop CPU.
I have a Dell Inspiron 8200 and I'm very happy with it. I highly recommend he look into it. I also recommend he not get one with a desktop CPU. Those have to have the fans running all the time and still probably get too hot to run at full speed. I like the fact that the fans on mine only run about 25% of the time (under minimal CPU usage).