Kali, All-Seeing Eye, KQuery, and Gamespy Arcade (*blech*

) are all ways of finding D3 servers without PXO, as is
this web-based browser. If you're really interested, though, I'd highly recommend
Vortex, a fan-made program that incorporates a server browser, level auto-download, and D3's official IRC chat channels.
Kali's pretty much the place to be for D1 and D2 games; its IPX emulation works flawlessly with both games. If you're going to run D1 on a modern machine, you'll need to download the
D1X 1.43 patch. For D2, I highly recommend
D2X-W32, a patch for D2 that is being actively worked on and frequently updated by Diedel. He just added D3-style CTF and Entropy into D2; definitely a must-see. You mentioned Kali's free trial, Omniscaper; it's actually limited to 30 days. Beyond that, you either have to get a new set of trial codes with a different e-mail address or pay the $20 lifetime fee. And when I say lifetime, I mean lifetime; some people have had their serial numbers for 10 years or so.

Phreak, it's highly possible to play multiplayer Descent using a mouse; in fact, some of the game's best players are mousers. It's definitely not easy, though; at least in my opinion, it has a much higher learning curve than a stick. I've never attempted to fly with a mouse myself. When you're comparing things, though, nothing is more difficult than flying all-keyboard; yes, there are actually excellent pilots out there who do so.
