I have used the [URL="http://restaurant.com]restaurant.com[/URL] iphone application several times with no issues at my local restaurants. It is so easy. There is a code 2DAYS to get the $25 gift certificates for $5.00
One thing that i have noticed is some of my favorites places have gone up from $35 in min purchase to $45. With my family of 5 this isn't an issue.