Windows 7 only: Windows Explorer's context menu is handy, but if you'd like easier access to your most-used features, CustomExplorerToolbar can put a number of different buttons right in Explorer's toolbar.
To tweak your toolbar, just download and start up the portable CustomExplorerToolbar program, and pick an option from the top menu. You can either add or remove buttons, and set which version of the toolbar you're adding them to or removing them from. Then, select the buttons in question from the menu, choose the folder types it applies to, and hit "Do It!"
So, for example, if we want to do what's pictured in the above image - remove the "E-Mail" button and add the "Properties" button - we would first choose "Remove the specified toolbar buttons" from the top menu. Then, we'd check E-Mail on the button list, and select all of the folder types (since I never, ever use this button). Then Hit "Do It!" Next, switch the top menu to "Add the specified toolbar buttons", de-select "E-Mail" and select "Properties", and hit "Do It!" again. This will add the properties button in place of the button we just removed. You can add or remove as many buttons as you want, space permitting. When you're done making your changes, just restart Windows Explorer to see them in action.
CustomExplorerToolbar is a free download for Windows 7 only.