If you've ever had a friend with an HTC EVO 4G call you about a malfunctioning ROM and you've had to walk them through a fix, you know that it can be a hair-pulling process what with terminal emulator, adb, and hoping they are actually typing in what you're telling them to type.
But if you can walk them through to the Market to download droid VNC Server, you can take control of their EVO as soon as they give you the IP address. You'll want to have them disconnect from WiFi and do this via 3G or 4G unless you're feeling like setting up a VPN.
One of the great things about this is that when you go into programs that require text input (terminal emulator/shell, SMS, etc.), you will be able to type using your computer keyboard and not be slave to Swype, T9, or the Android default keyboard and all the autocorrections that come with them.
You can connect with a VNC client such as TightVNC or RealVNC, or just plug the address into your browser and run the applet. The app has the standard VNC options: password protection, changing server ports, start on boot, and also the ability to disable the advertisement at the bottom.
It's worth a look if you're having to support your very own circle of rooted EVO-wielding friends. There are many other VNC servers available for Android now, but this one has always worked well for me.