I don't know how hard these are to find, as I bought mine 11 years ago brand new. Still, I thought I would let folks know that this one is available.
For HPCers, the 3C589C is the standby when it comes to wired LAN cards. HPC:Factor has drivers and patches available to utilize the card with CE 2.0 through HPC2000.
Odd, I thought I read somewhere that the NE2000 cards didn't get along with WinCE very well. :+/ My mistake. Exactly why is the 3C589C crap? I haven't had any problems with mine.