For those of you who own an S60 phone, there is a version of puTTY available for S60 3rd Edition.
I have an E90, and puTTY actually works really well (on the internal screen at least). It's obviously not as practical as using a PC, but for geek value it's right up there....
puTTY for S60 can be found here: http://s2putty.sourceforge.net/