How many startups does it take to screw in a light bulb? Probably just one, but while nobody's created screwinalightbulb.com, it seems like there's a new Web 2.0 startup to do just about everything else. Today's example of a service you didn't know you needed? BuyYourFriendADrink.com, which lets you... buy a drink for a friend online.

Here's how it works, you login to the website and order a drink for a certain dollar amount. Your friend is sent a code that can be redeemed at participating bars. Right now, about 40 bars in and around New York City are signed up, and the company plans to expand to other metropolitan areas later this year.

But does it work? WebWare's Caroline McCarthy reports that it does. She received a code as a text message, showed her phone at a New York bar, and the bartender entered the code into the bar's credit card system the same way she would for a gift certificate.

While this might not be that useful in everyday life, it's nice to know you can buy your friends a drink even if they live in New York and you're in Chicago. Or perhaps it's a good way to make sure you don't drink too much on a given evening. Just send yourself enough money for two or three beverages before you head out and leave your cash and credit cards at home.

[via WebWare]