If you are interested in the UNIX desktop and prefer KDE as I do, KDE4Daily may be just the thing for you. KDE4Daily is a QEMU virtual machine image built from the daily build of the most current development in KDE (currently at KDE 4.1).
This is what is often called “the bleeding edge” (an expansion of “the cutting edge”) – that is, the only guarantee is that there is no guarantee. The KDE build comes with a built-in bug reporting tool that activates when some part of KDE crashes.
KDE4Daily is a neat way to get and use the latest KDE build in a relatively low hazard way. I plan to see how it runs for me – somewhere.