I used to be disappointed that I couldn't copy the calculation results from Spotlight if I'm doing a quick math problem in it. Well, now with Lion, since you can drag everything else out from the Spotlight results menu, you can also drag calculation results.
It will drag into any text editor or I'm assuming anything that accepts text. Still would be handy to be able to copy it, but this is a huge time saver.
[crarko adds: I tested this, and it works as described. I also tried it in 10.6.8, and as indicated, it does not work there. It seems to be best to click on the little calculator icon in the Spotlight menu and drag that. I used both TextEdit and BBEdit as targets for the drop.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20110927040205968