I recommend cutting your own cross over cables. If you have several open PCI slots on a machine, this is actually a very cheap option (since, if you can't find used network adapters and cat 5, you're way out from civilization).
My junk pile runs Win 98, 2000 Pro, Mac OS 9.1, and Mandrake Linux 8.2. The 2000 Pro machine is the traffic cop. No router.
With PC Mac LAN, you can run Mac programs off an NTFS partition on the server, which is good, because putting a new HD in the Apple is just a waste of money.
Never really tried the same with Linux, probably because I have yet to use it for any purpose except to say I have Linux (still running under 2 Gb of Linux progs, and so far only GIMP has really impressed me).
BTW -- the define-a-user issue is a security advantage of 2000/XP. Otherwise, any dimwit who comes along the network can log onto your computer.
Really, it's a huge hole in 95/98/ME (jinx! whew! warded off the Millenium cooties). Basically, on any broadband system, anyone can get in. We used this to print really nasty porn out on other people's printers (OPP, anyone?) in college dorms. This only stopped when we realized that finding the appropriate drivers was rather tedious for something that was supposed to be the equivalent of a prank phone call.
