Firefox: If you hate having to search through your folders every time you change the type of file or directory you're saving to—and we certainly do!—Save File To helps you make custom context menus for file saving bliss.
Windows: If you've found yourself wanting to send a song to your XBMC playlist or a start a video playing right away instead of navigating the menus on the XBMC, send2XBMC lets you beam a file or URL from Windows to XBMC.
Windows only: Explorer extension Lammer Context Menu adds a number of very useful features to the right-click menu, from standard stuff like Copy Path all the way to wild cards, batch rename, and mounting virtual drives.
Windows: JDContextMenu is a small application that adds a variety of useful shortcuts to the right-click context menu in Windows.
Windows only: Portable system tweaking utility ShellMenuNew displays a list of all the items in the Windows Explorer "New" menu, and allows you to disable them easily.
Windows only: Previously mentioned VirusTotal Uploader automatically uploads any file to online virus scanner VirusTotal, scanning it for viruses with 41 different popular antivirus applications—and now it's even better and faster, with instant hash checking, letting you skip uploads altogether.
Firefox only (Win/Mac/Linux): Firefox extension Print Context Menu adds the Print and Print Preview options directly to the context menu—so even if you've consolidated Firefox's chrome, you can still print easily.
When we showed you how to master Windows 7's new Jump Lists feature, there was one extremely useful tip that we left out: you can also access them from your keyboard.
The Tweaking with Vishal web site writes up a quick, but useful, registry hack that adds an "Open File Location" item to the context menu, just like Windows 7 or Vista has already.