Outgoing and adventuresome types who don't like lunching alone might want to try out Noonhat, an experimental site that connects people looking for midday companionship. (For lunch, you pervert.) The site launched nationwide during Gnomedex. It's simple to use: you locate your position on a Google map, select the radius you're willing to travel for lunch, and enter in your e-mail and your desired lunch date. On the morning of the date, you're sent a notification with e-mail addresses of people looking to dine in the same area, if there are any.
And that's it. You can't specify interests, gender, or anything else of the sort, but once you connect on e-mail you can obviously beg off if you want to.
This site would work better if it were integrated into an existing network. As a Facebook app, tapped in to your social net, it'd be awesome. As a standalone lunch-date finder, it's a bit too random.
And if you're looking for companionship but the whole Match.com thing isn't for you, you might want to check out these other oddball meet-and-greet services:
PairUp (review). If you can handle a solo lunch but not a business trip all by yourself, this site will help you find a travel companion from your existing network of contacts (both you and your potential companion must be users of the service).
AirTroductons. Here's another site to rescue you from airline seatmate roulette. It's a matching service for people who want more control over who they sit next to on an airplane. The site is currently offline for updates.
Hitchsters (review). If you couldn't connect on the airplane, perhaps you'd like to try a taxi ride with a stranger. Hitchsters connects you to other people going to or from the airport via taxi. New York only, so far.
Flirting in Traffic. This old service lets you get contacted by people who eyeball you when you're cruising by in your rolling babe (or guy) magnet. You get a sticker with a URL and an ID number, and you put it on your car. Interested people can then contact with you via the site. I'm surprised this site hasn't yet made an appearance on Entourage.
Finally, see PicnicMob (review). This one's a little less scary than all of the above: it organizes picnics when there are enough people who want to get together at the same time. The site even tries to seat you next to someone compatible. But unlike these other services, you're not locked into a one-on-one in a restaurant, plane, or car. You can always talk to another person next to you.