Has anyone seen these? You can often get $25 "gift certificates" for $5, or a couple bucks more. Apparently you can't use them for alcohol, tax, or tip, but still...if you can save 20 bucks on a $50 meal, that ain't a bad deal. But do restaurants actually take them? Are there any unforseen hassles or embarrassments? I got 2, one to Thyme and one to Aubriot (in Chicago)--I guess I'll find out for 10 bucks, but I thought I'd see if anyone else had experience here.