Well there's a bit of freeware out there than can do that, Deskpins does it. Also xNeat's windows manager has the ability to keep windows on top and even change transparency and I know it definitely works with QT, there's a commercial and a freeware version, the freeware version does what I need it to do and I'm running it on Vista x64 with no problems sooo I guess that can help you out.