Maybe you rely on instant messaging to keep in touch with friends and family. You're not alone. Unfortunately, shared computers might not have the instant messaging program you use. In that case, head over to Meebo. You can communicate via a variety of popular instant messaging programs. And there's no software to install!
At some time or other, you'll want to create a PDF file. They're great for sharing because any computer will open them with the free Adobe Reader. PDF-creation software is pricey, though. doPDF is a free program that will create PDF files (but not edit them). It is listed as a printer, so it works with virtually all Windows programs.
Find out what hardware and software is installed on your machine with Belarc Advisor. It will also tell you the last time your computer was scanned for viruses. See a list of Windows updates or recover lost product keys. You probably won't realize how helpful this program is until you need it.