Heading home for the holidays?
Take a look at PortableApps.com, a repository of free software that's modified to run directly from a USB stick. Not only will you find a nice anti-virus scanner to help you tune up your relatives' PCs (ClamAV), but you'll also get Firefox, Thunderbird, GAIM and other useful applications to help you keep connected.
Really, I just want everyone to run AV on their family computers. I just put that stuff about Firefox and Thunderbird in to tempt you into downloading the package. Heh.