Emate 300: i own one
I bought an emate 300 several summers back (2 1/2 yrs ago) and I think it's a great toy. My use of it comes and goes, but it's especially fun for trips and bringing to the local coffee shop.
You can get ethernet on it (i bought an old PCMCIA ethernet card for mine), but it's pretty slow. I don't think there's a free ssh program for it, but you can webbrowse (slowly) or telnet alright.
There are a decent number of games and program/utilities out there for free to keep yourself amused.
The best things about the emate are the built-in keyboard and durable shape. If you have big hands you might find the keyboard uncomfortable, though. They're build for kids' hands.
For speed and true useability, I'd consider getting a Newton 2100 with keyboard. Those have a 160mhz (err around there) strongARM processor. the emate only has like a 25mhz. BTW, if anyone knows a hack to get a faster strongARM into the emate..... that would be one awesome hack.