Echoecho is one of the most useful location-based apps on the market today. When you hear the word “location-based app,” chances are you are thinking about services like Foursquare and Gowalla. While these can be fun, their utility is rather limited (unless you really feel the need to collect virtual badges). Echoecho, on the other hand, was built from the ground up to solve a simple problem: finding out where your friends are.

While most of today’s location-based services were designed around the idea of the check-in, Echoecho takes a very different approach and allows to ask your friends where they are.

imageThe service offers free native apps for the iPhone (iTunes link), as well as Android, Windows Mobile, Symbian and Blackberry devices. The latest update is currently only available for iOS and Android, though. The app falls back to SMS if your friends don’t have the app installed, so you can even use it if your friends haven’t installed it yet.

Echoecho doesn’t force you to join yet another social network. Instead, it simply uses your existing contacts on your phone.

Where are you?

Here is the problem Echoecho solves: Say you want to meet up with a friend in the city, but you don’t know exactly where he is. Today, you would probably send a few SMS messages back and forth to slowly triangulate where you both are and to decide what a convenient place to meet up would be. With Echoecho, you simply send a ping, get an answer, propose a meeting location and head there – all within a minute or two and with just a few clicks.

Where should we meet?

imageThe latest versions of the service’s iPhone and Android apps just arrived in their respective app stores. This new version takes the original concept of finding out where your friends are one step further. The app now also allows you to find, suggest and confirm meeting places with just a few clicks. While ensuring your privacy is at the heart of the service, the new version also allows you enable automatic replies for your best friends, spouses or children, so that the app will automatically tell them where you are.

If you want to discuss the meeting place in more depth, Echoecho currently still falls back to using text messages, but one of the next updates will move these discussions to a text chat in the app itself.

One minor limitation of the app is that it currently only revolves around one-on-one meetings. There is currently no way to easily use the app to poll a group of people about their locations and organize meetings.

Version 2.0 of the app now also sports a slick redesigned interface. In my first review, I praised the app for its simplicity and thankfully this has not changed, even as the team added more features.

To fully understand the power of this concept, you really have to see the app in action. Echoecho co-founder Nick Bicanic demoed the update at the Launch conference last month: