Lovely feature!
I just discovered that Kicker has a lovely new feature in 3.5. I always have a menubar-on-top with pager, systray, bookmarks and clock configuration, which goes well with an auto-hiding panel with some icons, taskbar and trashcan at the bottom.
However, until now, this arrangement made it quite hard to do something near the bottom of the screen, because up would the autohiding kicker pop whenever I wanted to grab the bottom of a window or click on XEmacs command line. Not handy.
Something close to this feature already was available in KDE 3.4, but there it wasn't usable with an autohiding kicker. Take a look at the 3.4 screenshot and spot the essential difference:
Of course, it would be even nicer if I could add two corners, instead of just one. But, well, I have to way that I'm very happy already.