Jag - the PowerBook gets quite warm. Play with one for a while and you'll see.
Xug - you're spot-on.
Probably the biggest reason I want to build a P4 system is because I haven't done it yet. I've built everything from 486's up to some pretty fast Athlons but I haven't touched a P4 yet. The Athlon XP 2600+ has me reconsidering whether or not I'll go with a Pentium 4, simply because it <b>is</b> that fast. But I must have built 20 Athlon boxes, so it's just not that exciting...
Ah, decisions, decisions...