This is more a note for myself, but in case other people are trying the same, here you can find some useful links.
After you enroll in the Developer Program offered by Apple, you get the chance to run your beta apps on real devices (iPhone, iPod, iPad). These can be your own development devices, used for testing, or can be devices owned by your customers, partners, etc. Apparently you can bypass the appstore and distribute your app to up to 100 different devices, through what's called "ad hoc distribution".
There seem to be quite a few resources on the web describing the process and any potential gotchas. One particularly useful link appears to be this.