This tutorial by Redmistpete explains how to add GnoMenu which acts as a "Start Button" application to bunch all of your apps, settings, and launchers in one easy, eye-candy place.It can be tweaked with skins, icon sets, buttons and transparency as well as applying any open/close animation from the compiz-fusion library!
How to add GnoMenu
After Ubuntu 9.10 (Karmic), GnoMenu is pre-installed. If not, get the .deb package for GnoMenu v2.0 or above and install.
1- right-click the panel and select "Add to Panel..." (choose whichever panel you wish to place the Menu on - multiple instances are supported).
2- Scroll down and double-click "GnoMenu"
3- the menu can now be dragged to a convenient place on the panel (it may be necessary to 'unlock' any other items if they are in the way - just right click the and un-check the "Lock to Panel" box)
4- right clicking the GnoMenu icon allows configuration and locking it's position on the panel,
5- left-clicking the GnoMenu icon activates your new 'Start Menu'