Every find that you are running out of disk space but don't exactly know what is taking up all the room?
SpaceMonger is a small windows app that lets you visualize the contents of your disk by representing you data by blocks with a size proportional to the space they take up on the disk.
Check this site to find the parameters you can use on the command line with WinZip. Especially useful when making batch files that need to compress or decompress files.
SyncBack Freeware is a great free backup utility for windows. You can create fully customized backup or synchronization job that will either run manually or automatically as scheduled windows tasks.
Since Scram Disk doesn't support XP here is an alternative: TrueCrypt. It claims to work on Windows XP, 2002, 2003 and 98 so it apparently covers the whole spectrum. It also seems to cover the same functionality and more. I haven't checked it out yet but I will soon. Just a heads up.
A good free disk encryption utility is Scram Disk. It creates a virtual disk on which everything you place is encrypted. So you can place your CV and all your online receipts on your encrypted disk Z:\ and should your computer get stolen well they only got the hardware and not your personal data. The only problem is it only works on 95/98/ME/NT/2000.
Drop to DOS is a little app that lets you right click on any folder and, by choosing the Drop to DOS option, lets you open a command prompt within that folder. Works with Win9x/WinME/WinNT/2K/XP.
From TeraByte Unlimited's Freeware site, where they seem to have more utilities but I have not tried any others yet.
The Offline CD Browser by Anders Software is a little app that lets you catalog your CDs and search through them as if they were all connected to your computer at once.
This is great for cataloging backups, music, pictures, etc. You can search by file name, file type, size, date, pretty much what you would expect. I will then indicate on which CD the files can be found. It will even tell you on which "physical shelf" the media is on, if you bothered to enter such information.
And this excellent piece of software is freeware.