I don't think Intel's P4 is a bad chip; but on my budget for what I do, it's a waste. And if I was going to shell bucks on some new hardware, the Athlon 64 2800+ or 3000+ makes a lot more sense, with a matching MSI K8N Neo board. Together they cost less than the equivalent Prescott setup, and do more.
Since I didn't want to pay that kind of money (getting married puts you on a bit of a budget), I just bought an Athlon XP-M 2500+. Because it's mobile, it's unlocked from the factory. I'm running it rock stable at 2075MHz (12.5 x 166MHz bus) at stock voltage (1.45v, desktop XP's run at 1.65v) and it's running 10-15 degrees (Celsius) cooler than my desktop Athlon XP 2500+ was at stock speeds. My board lists it as an "Unknown CPU" if I run it at any speed other than stock, but it works perfectly with it. Perhaps at some point I'll go from PC2700 Corsair ram to PC3200 and play around with 200MHz bus speeds; for now, it does a doggone good job.
Intel Q9450 @3.2GHz, Gigabyte GA EP45-UD3P, 4 x 2GB G.Skill @4-4-4-12
Antec P160SW case (modded), Xigmatek 750w PSU
3x 500GB (RAID-5), , OptiArc 7200S, ASUS E818A3T
Creative X-Fi XtremeGamer, Hauppauge HVR-1800, Radeon 4890