Ah, a person after my own heart.
You really need to give it more disk space for it to be really useful, try and find some old SCSI disks and you should be able to do something with it.
Here are some suggestions:
1. An IPX makes an excellent low volume firewall. There's a variety of free firewalls you can install, I like ipfilter (.
http://coombs.anu.edu.au/~avalon/)
2. It can make an acceptable file server. Two (not exclusive) sub-options:
- NFS
- Install Samba (
http://www.samba.org/) if you have PCs needing access to reliable centralised file and print services.
3. Print server
4. Departmental web server (Apache/ PHP/Perl etc...)
I'm sure there's more that you could do, but the above is a good start.