Today we launch Basecamp Mobile for phones and devices with WebKit browsers. This includes the iPhone 3GS, iPhone 4, iPad, Motorola Droid X, Motorola Droid 2, Samsung Galaxy S, HTC Incredible, HTC Evo, Palm Pre 2, BlackBerry Torch, or any other device running iOS 4+, Android 2.1+, webOS 2, or BlackBerry 6.
Basecamp Mobile is not a native app, it's a web app. All you have to do is visit https://basecamphq.com on your mobile phone. No apps and nothing to install - it just works.