My buddy Andrew over at the GaugeCam project has gotten me addicted to Virtual Box. I recently got a new computer (Dell Latitude e6500, 8Gig RAM, Core 2 Duo). I have Windows 7 installed and I like it, but I have a need to run both Windows XP and Ubuntu Linux 10.04, too. Andrew showed me how to install them both in Virtual Box. It might be just a passing fad, but it fills a huge hole that has existed in my computing world for a long time. I had not looked at virtualization for several years. The last time I tried it, the things I wanted to do were either too expensive or not possible with open source/free options. So I ended up dual booting between Windows XP and Ubuntu.
Lately, I have been doing some cross-platform development on Linux with QT Creator and OpenCV. I had to reboot the computer every time I wanted to test something out in Windows. Now, I can develop in whichever OS I want and test it out in a window that runs the other OS. All the stuff I use including all the hardware just works. I recommend it highly. I have only been doing it for a matter of weeks now, so I have not seen the snags that I know will raise their ugly heads, but the overcoming of a years long headache has me in a rather euphoric mood for the time being.