You probably have our own little ways of saying Hello or Goodbye, or maybe a casual signature, which you follow when you compose mails. Knowing that you use that same set of sentences over and over again, Outlook 2007 has a feature called Quick Parts, which lets you save such sentences so you can use them later.

While writing a mail, highlight the text you want to save. Click the Insert tab on the Ribbon. Click on Quick Parts and click "Save selection to Quick Parts gallery". To access any of the selections you saved, click on the Quick Parts button again and choose a selection.