Add Sticky Notes Avoid Sticky Situations.

Even the best minds are liable to forget something. Instead of wasting all those color-coded bits of paper, use Windows 7 Sticky Notes. Enjoy the variety of seven fun Sticky Note colors by right-clicking the note.
Need another reminder? Click the + sign in the top left corner of the existing note to create a new one.
To access Sticky Notes, run StikyNot.exe or click Start → All Programs → Accessories → Sticky Notes.

Show Desktop button

Power users will be familiar with the frustration of having to minimise countless open windows to take a quick look at newsfeeds or other gadgets on the Windows desktop. The revamped Show Desktop button – which now occupies the few remaining pixels between the System Tray Clock and the right edge of the Taskbar – makes all open Windows transparent when you hover the mouse over the icon. Ideal for a quick peek at the football scores before ploughing on with work.

Gadgets, Stickies, Calculator, and Screenshots

This Video Shows various new features in Windows 7.
Gadgets where also there in vista but in Windows 7 the slidebar of the gadget has been removed which makes it more attractive.

In Windows 7 you can add Calander, Clock, CPU Meter, Currency, Feed Headlines, Picture Puzzle, Slide Show, Stocks, Weather, Windows Media Center these are all the items which you can add it as Gadget on your Desktop.