When I type `uname -a` it says 2.6.17-5.
... that's not all it says. Those numbers are the kernel version you get with
If you havn't updated it since, and the tone of your post suggests this, then you probably have Mandriva 2007, which was released with that kernel on 2006/10/03. If you picked it up prior to that date, then you have Mandriva 2006 and you've been keeping it up to date.
... for KDE source code.
Note: kde4 is revising the active desktop elements.
There is a niggle at the back of my mind that says you could use the root screen as a desktop, then run a slideshow program in it. I've seen this done with an aquarium program and metacity.