debating which one to put on and older p3 laptop using wifi

XPSP2. IMHO.

Windows 2000 does not include a wireless configuration utility. That means you have two choices for establishing a manual connection:

One) option is to download "sniffer" software, that detects wifi connections for you.

Second) option is to use the software either provided by your OEM or wireless card manufacturer to help setup and manage your wireless profiles.

Software for managing a WiFi network adapter from other vendors, than XP's, can show you the signal strength of a network that is not broadcasting its SSID and that you are not connected to.
Good for troubleshooting.

both windows xp and windows 2000 are good OS'es. if you want the easy way and the all compatible way you should definately install windows xp. windows 2000 is more a server first client second.
windows xp was made more as an entertainment platform. and the worst things to set up is a working ethernet. and WIFi is worse that just LAN with cables. since its unsecure and then harder to configure. well. Microsoft certainly tried and made a good product with windows xp and the wifi compatability system. and SP2 helped it alot

Best Regards
E.S

Definitely XP SP2. Microsoft hit the nail on the head when it comes to access point/key management. Just make sure you don't install the wireless card's proprietary config tools; the driver and XP SP2 are all you need.

XPSP2 as the above stated especially with wifi.

Looks like I'm the only one who thinks W2000 SP4 then :\

IMO, I find that WXPSP2 is aimed towards novice users, who don't know how to tweak things and mess around with things.

While this is great for the aforementioned users, I would say that W2000 is much better for 'pros' (for want of a better word), but DOES require work to make it suit each indivuals needs

XP SP2 is gear towards novice users and requires much tweaking to get it to the 2000 usability level.

In terms of interface IMO 2000 is designed for 'pros'. In almost everything else XP excels, simply because it's NT 5.1.

As Malaris stated it's really up to the individual/hardware/situation your in.

I'm all about that .1