I like Gary's setup. That is a newer version of the emachines that I have (Gateway owns emachines now). Mine is an M6805. Still works great. The only complaints are weight and battery run time. But, if you get a "desktop replacement" type of notebook computer, then the extra weight comes with it.
If you do a lot of traveling, I like my Thinkpad.
But, I might suggest waiting at this time. Dual processors are becoming more popular (as the previous post noted) and the new Windows Vista software will be released (maybe early 2007). As a rule, if you buy after the holidays, you get better deals. Such a dilemma buying a new computer; as soon as you buy it, it becomes obsolete.