LoL, I have a cheap Toshiba Satellite Laptop that i use for when i am traveling. spent about 400$ usd on it. Granted it will not win any marathons, but it runs maya just fine if you can deal with a lower resolution and a vit of view port lag.
I do recommend though getting a mouse and not using the touchpad, because well. that's just....impossible. for me atleast.

Basically i say Drop alot of money on your desktop machine, if you want a laptop just get something that will get you by for traveling or what not. Doing large amounts of work form a laptop is impracticable anyway imh.

G-man