Excel Fill Down Command hotkey

If you need to input the same data - text or numbers - into a number of adjacent cells in a column, the Fill Down command can quickly do this for you by just using the keyboard.

• select a cell
• Press and hold down the Shift key on the keyboard
• Press and hold down the Down Arrow key on the keyboard to extend the cell highlight from cell D1 to D7 (or press Shift, Ctrl-home to the bottom of the content).
• Release both keys.
• press Ctrl-d

Reference:
http://spreadsheets.about.com/od/tipsandfaqs/qt/81130filldown.htm