If you use a laptop, you should really really encrypt all your valuable data on your computer.
and should make it a good practice to do it on all the computers you use.
with the rise of identity theft, and stolen data. The only real defence is encryption (in addition to all the good security practices)
and on that note:
with Microsoft Windows 2000 and XP pro. you have 'EFS' which is build in crypto. With Windows 2000
based EFS being very weak and breakable. Windows XP pro SP2 based EFS configured correctly (no local recovery agent) is pretty secure. but has limitations and weakness's.
other then windows based EFS you have 3 basic choices:
Kremlin ->http://www.kremlinencrypt.com/
PGP -->http://www.pgp.com/
GPG -->http://www.gnupg.org/
with GPG being an an open source version of pgp and is a command line version with some Gui front ends and plug ins. it cipher strength is generally weaker then pgp and kremlin.
Kremlin crypto strength is very strong symmetric crypto and is what is considered "Military grade" with the added bonus's of a secure text writer, and a security "sentry" that secure deletes, wipes free memory and free hard drive space etc.
PGP is asymmetric and is based on the openPGP protocal is pretty secure and is also feature rich.
-Nex6