[Article updated to reflect regional availability of application.]

The (very) short list: Booyah, Facebook Places, Foursquare, Google Latitutude, Gowalla, Loopt, and Twitter geo-location. Oh, and now Geomium.

Available in the UK, US, and continental Europe, Geomium is the latest startup company to try its hand at building a location-based social network, a model with dozens of innovators and probably even more imitators.

But Geomium thinks it’s bringing something new to the table.

Drawing data from Yelp, Qype (basically a Yelp just for London), and Eventful (an online event finder), the new location service has the advantage of launching with an established collection of useful features. Often the hardest part of starting one of these services is accruing the necessary base of initial users.

As in many social location apps, Geomium users can see where their friends are and chat with them, meet new people, and discover nearby bars, restaurants, or events.

Geomium is currently only available for iPhone, but the app is coming soon to Android, Blackberry, Nokia, and other smartphones. The strict London launch will be followed by launch in other UK cities by early 2011. European and United States launches come after that.

Some forecasted that Facebook’s entry into the market, with Places, would shatter all the hopes of any fledgling startups and greatly inhibit further growth of even the most established services, like Foursquare.

Geomium CEO Michael Ferguson doesn’t seem to think so:

The future is very bright for new entrants into the market that can deliver a strong and useful location-based services (LBS) proposition that will help make the everyday lives of people better. It will be much easier to create a new community based around the full potential of LBS rather than try to convert an existing community, who signed up to a service for a different product.

His last point seems to be a jab at Facebook for trying to add a layer of location to its social network, an attack that might not be entirely fair. If people originally signed up for Facebook to connect with friends online, then one can easily imagine shared location being a part of that experience.

At the same time, what with the issue of privacy concerns constantly lobbed against Facebook, Ferguson could have a point. The best location-based service might be the one wholly dedicated to that concept and built from the ground up towards that end.