There are a couple of other things that VMWare-tools does for you:
1. Allows you to synchronize time between your guest and host OS-es - This avoids having to run an NTP daemon on every guest instance and also allows the host OS to correct the clock drift that you get under VMWare with some Linux distros. VMware actually
strongly discourage having any sort of software-based clock sync on guest instances. The ISP I work for has a
huge VMWare ESX hosting farm and you wouldn't believe the problems we get when our clients sysadmins decide to install NTP on their hosted VMWare servers.
2. Enables copy and paste between the host and guest OS - probably a small thing as far as we on this forum are all concerned, but again, can be a huge time saver in a major 'Enterprise' VMWare deployment.
EDIT: I've just fired up my vmware-server install and launched an Ubuntu 7.x guest instance I've been playing with. The vmware-tools virtual CD that you get contains both RPM and tar.gz formats, which is exactly how ESX-server does things. You should find that the RPM install of vmware-tools will work without a hitch on most RPM-based distros, and it saves having to b*gg*r about compiling stuff.

EDIT #2: Just thought of something else that vmware-tools does for you - it enables the 'shared folders' feature, which allows you to have access to specified parts of the host filesystem from within your guest instance. This can be extremely useful for cross-platform development work. You code in Linux and flip over to your WinXP guest to check compatibility.