Downloaded the latest QT Creator and installed it (without sudo) alongside my older ones, in my home dir. Then I found I couldn't build some of my apps, because of an error: ‘Quit’ is not a member of ‘QKeySequence’. A little Googling suggested that Creator was trying to build with an older qmake, or against an older version of QT4. The new version of QT Creator is 2.0, but it Abouts itself as "QT 4.7", although the QT4 version shows as 4.6.3, which is really confusing. In the end, I deleted the new install, and re-installed with sudo to the place it wanted to install to, in /opt. Then I specified 4.6.3 as the QT version, and I was able to build my dom application. I still don't have a QT version in my path; I'm not sure whether that's a good thing (because I often upgrade QT and have different versions on the system) or a bad thing (because QT libraries are occasionally not found, which could be the cause of various problems in building the Phonon example). We'll see...