Keep in mind that it's not just the battery life that's the problem with desktop processors in laptops . . . it's the HEAT. Putting a desktop processor in a laptop effectively makes it a desktop, since it'll burn you if you put it on your lap. I'm surprised Dell hasn't had any of MacDonalds' troubles in that regard 😉 Also, if you really get down to it, it's not even so much the discomfort as the longevity and dependability. I've had almost every single Dell with a desktop processor I've ever seen down at ResNet go back to Dell because it was overheating and shutting off. Celeron, Pentium . . . doesn't matter. Desktop chips are called that for a reason.
Note that this is not just with Dells . . . Compaq, HP, Toshiba, Sony. They all do it, and they're all just as bad. If you HAVE to get a PC laptop, get a mobile processor or a Pentium M. The Mobile Athlons (not the 64) have a TDP of 35W, which is a lot more than the Pentium M and G4, but I think it's less than a mobile P4 . . . I could be wrong, though . . . The overclock like stink, though 😀 (see sig and add 300MHz for the top end . . .)
The only thing I can say about buying a laptop at the end of the day, though, is just to make sure you need what you're buying. I regret the amount I paid for my PowerBook. I love it, but I want the money back. Had they been making the G4 iBook at the time, I'd have gotten that. But if you're looking at similarly priced PC laptops, there's not much of an issue . . . But for me, as a college student, I figured I needed a laptop. I think I'd have been much better served with a good desktop and a cheap Pismo or something.
Z