What it does: excludes search results with a particular word or phrase
What to type: bass -fishing
bass -fishing
What you'll get: results about bass that are not related to fishing
What it does: searches for web pages that include either word
What to type: vacation London OR Paris
vacation London OR Paris
What you'll get: results with the word "vacation" and either "London" or "Paris"
You can also choose from the popular tags.