There are still a couple days left to enjoy web based applications and games for the iPhone, you know before the App Store opens. Here is a simple but addictive game called Mass Defense for your iPhone:
Mass Defense Action Browser game Optimized for iPhone
Mass Defense is an addictive physics-based action web game.
Events takes place in year 2036, when large asteroid cloud attacks our solar system. Your mission is to defend the homeplanet from an asteroid rush using the most powerful weapon ever invented.