you can go here for kde screensavers (which you can run in xscreensaver):
you can run xscreensaver instead of kde. if you want to do that just follow these steps.
1. disable kde screensaver in kcontrol
2. create a little shellscript and put it in your ~/.kde/Autostart folder. remember to chmod that shellscript to be executable. for example sakes, lets call this script, xscreensaver_start.sh. to change the permissions: "chmod 755 $HOME/.kde/xscreensaver_start.sh" (no quotes)
the contents of the script will be:
3. to choose from the hacks (screensavers) in xscreensaver, run this command:
4. to lock your screen use this command:
both 3 and 4 you can make shortcuts to and put them on your kde panel if you wish. also gkrellm has a lock/shoot plugin that will lock your screensaver. if you want to lock it.