IRK works great with my Targus universal keyboard. Give it a try.
If you don't want to use SSH, Telnet is actually built into the Zaurus. There is no downloads needed, just edit your inetd.conf file to use the in.telnetd.
From
this link:To enable your Z's telnet server, edit /etc/inted.conf and add the following line ..
telnet stream tcp nowait root /usr/sbin/tcpd in.telnetd
bear in mind that everything you type and see in a telnet session is sent in the clear. This shouldn't be a problem if you're using the USB cable, but it's definitely a recipe for disaster over ethernet or on a wireless LAN.
As an alternative to telnet, you can use SSH. Download OpenSSH install it on the Z and then generate a key file:
ssh-keygen -b 1024 -f/usr/localetc/ssh_host_key -N ''
(NB: two single quotes on the end there) add the following to /etc/inetd.conf:
ssh stream tcp nowait root /usr/sbin/tcpd /usr/local/bin/sshd -i
and restart inetd with:
/etc/rc.d/init.d/inet restart