If you're a multi-tasker, you probably hate taskbar clutter. The Windows 7 redesign of the taskbar is an improvement, but not a perfect solution (and if you're using an earlier OS, it's no help to you at all). The free RBTray offers a nifty remedy for almost all Windows users, giving you the option to minimize programs to the system tray instead of the taskbar (where minimized programs usually go), simply by right-clicking the minimize button. It's great for programs like e-mail clients and media players which you always want running, but don't want in your way.
RBTray works just as a simple enhancement should; it is incredibly lightweight, using minimal resources, and so unobtrusive you may forget that it's running. RBTray doesn't even put itself in your tray (or the taskbar for that matter). RBTray's one shortcoming is that it doesn't work with heavily skinned windows like Winamp and iTunes, but these types of programs usually have built-in tray options anyway. Otherwise, RBTray is a handy piece of freeware which will help you keep your sanity while juggling multiple windows.