Few days ago I've heard about a Symbian port of Putty, obviously you alread know what putty is and what you can do with an SSH terminal emulator.
I think it's one of my favorite software pieces for Win32 machines, now there's a project aimed to port putty on Symbian OS machines, I've tried to install it into my samsung phone even if it's not supported or mentioned, results: clear, it doesn't work but the project seems promising.
At this url:
you can find S2Putty, it's a nice project and they've firstly released some code and ports at the beginning of the year, I'm now waiting other ports for Symbian based cell phones, I'll hope to get something for my platform too.
By now I'm getting control over my linux box by using a web browser (Opera for Symbian is absolutely outstanding) , few web services and php pages, but maybe an ssh client has more benefits and it's more useful for doing everything (and even more secure)
Take a look at the project, try to install in your phone if you're one of the lucky guys and drop me some notes so we can share impressions about it, I'm now trying to grab from someone a Nokia N95 and try to install there