A 64mb usb drive is enough to install vim, which is my favorite editor in any environment.

Alternately, you can use ssh to connect to a remote server and use whatever editor you like. I recommend putty , which is only 412kb and doesn't need to install anything.

The prices on USB drives has fallen dramatically, so you could upgrade to a 1GB drives for $20. The 256mb drives will probably start showing up in cereal boxes in a few years. ;-)