Prominent online project management service Basecamp has launched a free mobile web app, built in HTML5 and custom designed for users on a multitude of different handsets. It's attractive, easy to use and hopefully a model that will be followed by 37Signals on its other apps like Backpack.

Loading basecamphq.com on your mobile device will take you to the new version automatically. Makers of the several 3rd party Basecamp mobile apps, who were probably making a fair sum on their software, are unlikely to be pleased. I'm excited to use it though. I really hope it supports Backpack soon.

The company says the web app will work on the following devices: iPhone 3GS, iPhone 4, iPad, Motorola Droid X, Motorola Droid 2, Samsung Galaxy S, HTC Incredible, HTC Evo, Palm Pre 2, BlackBerry Torch, and any device running iOS 4+, Android 2.1+, webOS 2, or BlackBerry 6.