if you want something more than the usually k-menu, kbfx is what you need!
this is only an example of how you can personalize your kbfx. There’s a lot of theme in kde-look.org
you can install kbfx from repository: sudo apt-get install kbfx but the last release is the 0.4.9.3.1 find here. Before doing that you have to remove the repository version 
here you find something useful if you have some problems:
1.) Flash Demo http://www.kbfx.org/kbfx/demo/
2.) User’s Guide http://www.kbfx.org/siraj/KBFXslik.pdf
3.) Strigi Install Guide http://www.kbfx.org/siraj/strigi.pdf
after the installation, add kbfx at your panel like any other applet (right click on the panel -> add applet -> kbfx spinx)
when you have installed kbfx you can change the start button and edit it whatever you want. Create 3 images named normal.jpg, pressed.jpg and hoover.jpg, then with the configure menus of kbfx you have only to link the 3 images.
