How to use rdesktop (Windows remote desktop connection) - Ubuntu Forums:

rdesktop is a client program that allows you to connect from your Ubuntu computer to your Windows computer to remote control the Windows computer. In other words, while you are sitting in front of your Ubuntu computer at home, you can log into and access your Windows computer as if you are sitting in front of the Windows computer.

Wow, I have to say that Ubuntu is really ready for prime time. It works on my old Laptop without having to hunt down odd laptop drivers, it comes with productivity software installed, the package system for downloading additional software is easy to use, it can access my VPN, it can RDS (as seen above), and more! Really outside of MS SQL and MS VisualStudio I could do all of my work on an Ubuntu 9 machine.