Around here we all seem to be addicted to GTD applications (especially those that sync with online services). That's why it is only fitting that we would mention a new iPhone application named Outpost. Outpost manages your 37Signals' Basecamp projects on your iPhone.
Basecamp, as you might already know, is 37Signals flagship application for managing clients, projects, tasks, etc. However, with a native application to manage Basecamp projects I can definitely see myself using Basecamp more than I do now.
Outpost should be available on the AppStore in "early to mid August." For more information about Outpost, you can check out their website and development blog.