GigaBar is an application designed to 'fill the gaps' in the somewaht limited Pocket PC Today interface.
The program gives you a simple tool bar which allows you to open or close the majority of your applications with a simple click. It uses icons to display the most recently opened applications and to give you direct access to your explorer program.
Some of GigaBar's most popular features are that it's completely free, 'non proprietary' (meaning that developers are free to tinker with it or add more features), and personalizable using skins.
Highly popular (but refreshingly small) add-on for your Pocket PC.