Gmail out of office

Gmail: Help Center - How do I set up an automatic vacation response?

So Gmail now has an "out of office assistant." It's actually kinda cool. It'll e-mail people when you're on vacation, but it only e-mails them your vacation e-mail once every 4 days. Also, you have the option to only activate it for people in your Contact list so it doesn't send it to just anyone who e-mails you.