There is Boolean search in Spotlight. Ipse dixit has a couple of articles that discuss undocumented Boolean searches in Apple’s Mac OS X Tiger’s Spotlight. We’ve condensed them down and tested them on Mac OS X 10.4.1, Build 8B15. The following works:

NOT=! – Searching for apple!mac also tells Spotlight to find everything with “apple” but NOT “mac”
OR=| – Searching for apple|mac tells Spotlight to find everything with “apple” OR “mac”
AND=space – Searching for apple mac tells Spotlight to find everything with “apple” AND “mac”

Full articles with discussions here and here.

MacDailyNews Note: If you find other undocumented Spotlight features, please add ’em below. Happy hunting!