Things to keep in mind when using an external USB 2.0 drive:
Windows 2000 has a 32gb per partition limit on a FAT32 system. Learned this after 1.5 hrs of format time for an 80gb drive. Failed at 100%. *sheesh* I then partitioned it into 11/26/26/17 gb chunks and they all formatted nicely. (The existing internal 60 is partitioned as 10/25/25 gb).
Windows 2000 also has a 4gb filesize limit on a FAT32 system. After an hour of MSBACKUP - was to be an 11gb file of all the important stuff from all three drives - it failed after about 20 min - out of drive space. *sigh* So I made 3 separate backups, keeping each one under 4gb, and they all worked fine. Love these hidden limitations. At least that got the important portions backed up. The parts I dropped from the backup can be easily restored from CD. I could have used NTFS, which does not have the 32gb partition limit or the 4gb filesize limit, but then I wouldn't be able to use the drive on other machines as easily. I may end up reformatting it in the future, but for now this will suffice.
Next, a file by file copy of each internal disk partition to the corresponding external disk partition. Will take a while the first time through, but after that I should just have to connect the drive and re-synchronize them, using the internal as master.