Best for: Foodies focused on the next big thing.
Howit works: Sign up with this app (available for Android and iPhone and as a website) to receive twice-weekly e-mails touting a deal (30 percent off your bill, free wine with dinner) from trendy restaurants. You have 24 hours to claim each offer's pass code, which you then show to your server.
Downside: Procrastinators, beware: Most pass codes expire within a few months.
Average discount: 30%
Where it works: Chicago, Los Angeles, New York City, and San Francisco.