Our company has recently finished our first ever Ruby on Rails application: Pin in the Map.
The application makes it really easy to label a map point with some descriptive text, share it with your friends or put a link on a website. It even links to Google Earth!
I'm after beta-testers... if anyone's got a spare moment and wants contribute some useful suggestions, that would be great.
http://pininthemap.com. Hope you find it useful - I certainly will :)