Accelerators, a softer name for Smart Tags, are neat little shortcuts a user can use to perform an action based on some selected data, without having to cut and paste it anywhere else. For example, rather than paste an address into Live Maps, you can simply highlight 1 Microsoft Way and access an Accelerator to map out the location immediately. Accelerators for Windows made a quiet debut back in an older Milestone 3 builds of Windows 7 and can be found in leaked build 6780.
Just like in Internet Explorer 8, you select some text and access the available Accelerators by clicking the big blue button housed in a toolbar on the Taskbar (or by pressing Winkey+Shift). A menu will appear with the stock choices, allowing you to define, email, map, or perform other activities on that word or phrase. Easy stuff.
The next button over, sporting a grape-drink purple, gives access to Voice Shortcuts also accessible via Winkey+Ctrl. Use of a Voice Shortcut is similar to that of an Accelerator, no surprise as they’re tied together. You select some text, click the button (or use the associated shortcut) and speak your mind. If you’re lucky, it won’t confuse ‘define’ with ‘log off’.
Source:→ Within Windows