Wow! Now this is something I've been wishing for, for a long time now. I have two flat panel monitors at home connected to my home PC. I hate working off of a laptop screen for any long period of time. However, most of my work-related files and applications are on my laptop. So, I'm often moving things back and forth between the two machines so that I can use my flat panels.
The ideal solution would be to Remote Desktop into my laptop from my home PC and use the flat panel monitor. However, Remote Desktop in Windows XP doesn't support ClearType. Not having ClearType enabled on a flat panel just drives my eyes batty and makes it unusable for me.
I sure was excited to learn that now the Remote Desktop client in Vista supports ClearType! But that alone doesn't help out my home PC which still runs XP and will never run Vista (it's an old 600Mhz machine). No worries though, the Vista RDP client will soon be available as a download for XP once the final version of Vista is released.
In the meantime, if you're running Vista RC1, I've discovered that you can copy the RDP client bits over to your XP machine, and it appears to work just fine. From your Vista machine, copy the following four files into any directory on your XP machine, and run the executable (mstsc.exe) from there on XP:
Once you start up the new Remote Desktop Client on XP, click the "Options" button to reveal the settings dialog, then go to the "Experience" tab and ensure there is a check in the box for "Font smoothing" as in the image below:
Disclaimer: This is most likely not an officially supported configuration. I'm only sharing what appears to have worked for me on my machine so far. Be on the lookout for the official Vista RDP Client download once Vista is released.