For those that haven't used the quicklaunch widget, you need to take a look. The benefit of quicklaunch is that you can put 20-30 apps at your immediate fingertips in the space of 5-6 icons on the plasma panel (one-click access to all your favorite apps) Example:
In order to add it to your plasma (kicker) panel, rt-click the panel and choose 'Panel Options' -> 'Add Widgets', scroll down and choose 'Quicklaunch'.
It will appear at the far right end of your panel instead of where your mouse was due to a design flaw in the panel. To move it where you want it, go throught the same process, rt-click the panel choose 'Panel Options' -> 'Panel Settings' then you can move things around. (be careful not to click outide of the panel or you will have to navigate back to 'Panel Options' once again.
As a matter of preference, I put the quicklaunch right next to the start menu with the pager on its right:
of course you can put it anywhere, but when I think "launch application" I'm already programmed to go to the bottom left corner of the screen.
I put systray, device notifier, clock and cashew at the other end of the panel. Just a personal preference:
You can get rid of any other application icons you have on the panel, because they will now all go in quicklaunch. Also delete the show desktop icon -- you don't need it. If you set your pager settings correctly, then clicking on the current desktop in pager will "show desktop". (rt-click pager, pager options).
To setup quicklaunch, right click it and choose Quicklaunch Settings. Set the visible icons to a sufficient number (I use 24). It won't expand until you put the icons in it. To add your applications to it, just right-click on the quicklauch above the icon where you would like the new icon to reside. (the new addition will push the current icon down (or to the right if it is in the bottom row) when you add it. After you choose add icon, you are presented with a small file open dialog (click on the floppy disk button). Navigate to /usr/share/applications or /usr/share/applications/kde4 to find the desktop file to add. (kde3 apps are in /opt/kde3/share/applications) Just repeat the process until you have the icons you want.
It's not quite as good as putting a subtree from your menu in an icon on the panel (like kde3), but it is a good substitute until Will Stephenson's fix filters down from kde4 upstream. Try this quicklaunch approach, and I think you will find the convenience of the desktop improves quite a bit.
Good luck ;-)