I stumbled across this open source RDP (Remote Desktop Protocol) client for Windows Terminal Server. With this you don't need the expensive Citrix ICA software.
http://www.rdesktop.org/
patches exist here that will allow it to work with Windows 2000 terminal server
http://bibl4.oru.se/projects/rdesktop/
This is a great project, I don't know why it's not getting more exposure.
A company in Europe was once offering $20,000 to the open source community
to develop a program like this.
There is also a spin-off project call RDP2VNC that will let you use any
VNC client to connect to a Windows terminal server.