Don't break my third-party iPhone apps
...So why am I no longer concerned about Apple providing an official third-party SDK? Quite simply, I’m not concerned because a number of very bright, talented, and motivated individuals have managed to actually do the job themselves, without any help from Apple...
Hear, Hear... since the Beta Release of 'Installer.app' came out I've installed, tested and kept several 3rd party applications on my iPhone. I agree with the authors' assertion that the apps are clearly in Beta status, and there are still some rough edges to work out (mostly unexpected quits for me) but most are very usable.
The progress made with this release is nothing less than astounding, the install process is quick and painless, everything is fully automatic. All you have to do is connect your iPhone to your mac, download and run the installer (on your mac), reboot your phone and presto! You've got a new button on your phone called 'Installer', you can use this application to install new applications and keep already installed ones up to date with the (frequent) releases that improve the software and add new features.
I strongly recommend installing the 'Community Sources' and 'SummerBoard', which will give you access to all the applications and a (themed) scrolling home page so that you can fit more applications in the window. It's truly fantastic.
Updating software is a breeze, when you launch the Installer app it automatically checks for new versions of currently installed software providing you with a list of updates you can choose to install. The apps download faster over wi-fi, but since most aren't very large edge is perfectly usable as well if you don't have wi-fi available.
if you have an iPhone and you'd like to expand it, or just want to make it your own, check out this website and give it a go!