I've recently picked it up. I'm currently running Office 2000 along with Visio 2000. Are there any reasons I shouldn't just install 2003 on top of everything?
I had no problems doing an upgrade install. My version of Office 2003 didn't include FrontPage, so technically Office 2000 is still installed on my system but FrontPage is the only component of Office 2000 that is installed. If I run Office 2000 setup and choose Add/Remove Components then it reflects that FrontPage is the only Office 2000 program installed. So the Office 2003 setup seems to be quite smart about installing itself without causing trouble for any parts of Office 2000 that remain.
However, when I first ran Outlook 2003 it didn't want to pick up my Outlook 2000 mailbox file, instead it wanted to walk me through creating a new one and setting up all my accounts, etc. So I had to manually steer Outlook 2003 in the right direction.
I like Outlook 2k3 MUCH better than 2k. I also had to manually point it at the right personal folders file. You can do this after the initial install no problem.