Text terminal hardware (for Linux)

Is there any way to obtain a hardware text terminal (preferably small in size) with a screen and a keypad to connect to a Linux machine (preferably via USB)? I'd like to be able to log into a command-line and do some work there while simultaneously running a graphical environment on the main display. It seems like there should be some kind of LCD screen and qwerty keypad device designed for this purpose. Does this exist, and how do I get one?

Edit: I'd be happy with a small networked device as well, as long as I could get a remote terminal into my computer.

USB usually isn't used for the classic "dumb terminal" paradigm, although as Chris mentioned in his answer you could get a USB-serial adapter. The traditional terminal is old, CRT-based and large, and you want small.

Since your'e looking for small, try the Nokia N810 net tablet. My friend has discovered that he can use VNC with it to control his PC, you could just as easily use ssh or telnet to connect to your main PC. He's a DJ, and has a PC-controllable Yamaha mixer, and so will use the N810 to control his PC, which then controls his mixer... as your application would be far simpler, I would think it would be very doable. The N810 runs a modified version of Debian Linux, so you should be able to get a ssh client to run in its' terminal window (according to one forum post I found, it comes with a ssh client). Plus, you can do this wirelessly, which cuts down on the cordage. The cheaper Nokia N800 would also do this too.

Either that, or get a netbook, overwrite the OS with a Linux distribution that lets you use the commandline, and do the same thing.

You might consider getting an old Toshiba Libretto laptop and set it up to run as a 3270 or a VT52/VT100 terminal with an emulator program. You can either run Putty on Windows, run a terminal over a serial cable or you could even load up a version of linux and ssh from one to the other across the network. The bonus is the old libretto models are all cheap now. You could put a pcmcia wireless card in this which would unchain you from the tty cord.

This is super easy to do as there are a ton of terminal emulators out there.

I did something along those lines where I had the libretto plugged into TTY type console via a null modem cable and then plugged it into the network. I could RDP to the Libretto which I left in a remote location that was not convenient for me to visit in person. I could still hit the console just like I was right there.

I think the cheapest solution is an old laptop or netbook and an ethernet cable. On the software side you would need ssh(d). Serial cable is also an option, but more complicated to set up, espescially if you need to buy a usb-serial adapter.

If you want the cheapest there is, buy a 6.50 € USB phone and you'll get a keyboard, a screen, a sound card and a microphone. But you'll probably have to interface it, the screen is one line numeric and the keyboard, well, you know ... ;-) For 10 times that price, I bought several Toshiba Tecra 8000 out of which, although short on RAM with 256 MB instead of 512, I made very decent Ubuntu 8.04 computers for Belorussian people(Xfce4 but Gnome runs if you're patient). From that on, all that has been said above becomes reality. Thanks for the openID support !!!