Our tip today looks intimidating to most people, but may be a life saver to server administrators. If you're a server administrator, you would probably have used text-based terminal protocols like Telnet and SSH (Secure Shell). Did you know that your mobile phone can be used to connect to your servers via Telnet and SSH?
Here's the Telnet and SSH client software (free, open source) for your Java-enabled phone. Here's the list of supported phones. The console display is tiny, but it may be possible to run some simple checks or execute simple commands, just by keying the commands into your phone. Consult your security administrator if you're not sure if it's safe to access your servers remotely.
In theory it's possible to install an SSH server (like this one) on your home PC so you can control your home PC remotely with your phone via the mobile SSH software... but I wouldn't recommend it :-)