Great social coupons to sign up for before a U.S. trip.

Sites like Groupon and Living Social have deals at up to 50% off—and Fodorites know they aren’t just for locals. Fodor’s user lincasanova says it’s "best to sign up for your favorite cities early to take best advantage of more offers." DebitNM has used this for trips to Phoenix and San Francisco and reminds us that "most deals do have expiration dates, so keep that in mind and always read the fine print." Groupon serves mostly U.S. cities, but includes Canada and countries in Europe, Asia, and South America as well. Living Social has been expanding in Europe and dedicates its weekly Escapes emails to travel deals.