I can't seem to get OpenSSH to work on my 3Gs. I've tried restarting, installing sbsettings to reset the, reinstalling OpenSSH. All connection to the device is instantly rejected (as though OpenSSH is not installed). Is it supported at all and is anyone having the same problem?

I'm assuming OpenSSH is installed, your device is connected to a wireless network? Port 22 is blocked by default on most carriers so it's unlikely you will be able to connect to your device through the cellular data IP address over SSH -- at least, I've never been able to. I can only connect over WiFi. I use SBSettings to toggle OpenSSH so I can verify that works as well.

Are you on wifi or 3g/edge? Have you verified on the phone that OpenSSH is actually running?