I'm an American, and no, it's not cool not to tip here. Tips are sometimes part of wages earned in certain industries (bars and restaurants), bar tenders and waiters are actually taxed on tips, so unless you're some cheapskate, I would strongly recommend that you think twice about this as you might not get a great service the next time you visit the same restaurant or bar. I even tip in the UK which is generally not required, it a way to show your appreciation.