If you provide tech support for your family, you know this frequently needs you to remotely control their Mac and fix their problems for them. You could use Screen Sharing or iChat but unfortunately your relative's computer is behind a firewall. How do you set this up beforehand so it's not painful to talk them through the screen sharing activation steps?
What follows is a simple double clickable method to handle this.
There are a variety of ways you can approach this problem: for example, iChat and Sharing preferences both have screen sharing options. In the case of my relatives, however, they all live behind NAT firewalls and even run old pre-screen sharing OSX versions, so setting up the needed tunnels or trying to port forward the inbound VNC connection on port 5900 through their firewall is a nightmare to do over the phone.
Instead I use the 'reverse connection' feature found in some VNC servers. I use Vine Server.app (formerly OSXVNCserver.app). But even this is painful to talk through for a computer illiterate relative, so instead I created an AppleScript that activates it with just a double click.
do shell script "'/Applications/Vine Server.app/OSXvnc-server' -connectHost foo.foo.com"
Mac OS X Hints
http://hints.macworld.com/article.php?story=20101228210353668