Windows only: RecycleBinEx is a souped up Recycle Bin with Windows 7 jump list support that groups files according to the date they were trashed, making it easier to permanently delete items after a specific timeframe.
You can set RecycleBinEx to automatically delete files after a certain timeframe or you can manually delete files based on the time you sent them to the Bin, making it easy if you want to clear out files that you deleted 2, 7, 15 or more days ago. The app also sports some nice Windows 7 integration: If you pin the program to the Windows 7 taskbar, for example, you get a slew of jump list options. (Normal recycle bin options are also available without having to put a shortcut on your taskbar.)
Interestingly, if you're running multiple versions of Windows on your computer, RecycleBinEx also combines all recycle bins, allowing you to empty bins across different OS installs with easy file management and deletion instead of having to switch between operating systems. RecycleBinEx is freeware for Windows only.