There was a lot of debate last week when Apple rejected the Podcaster app for inclusion in the App Store, saying that it "duplicated iTunes functionality." Rather than taking a stand against programming iPhone apps until Apple's policies shift, like Exposure dev Fraser Spiers, Alex Sokirynsky decided to bypass Apple and distribute the app via Ad Hoc App Distribution.
Many developers use Ad Hoc App Distribution to insure that beta testers and reviewers get copies of their software prior to the App Store release. A developer takes the Unique Device Identifier (UDID) from your iPhone, does a little magic, and then sends you two files -- one contains the app, while the other is a provision file. You drag the provision file to your iTunes Applications window, followed by the app file. A quick sync with your iPhone installs the app, and you're ready to go.
Alex has set up a website where you can sign up to get an Ad Hoc distribution of Podcaster. You'll need to "donate" $9.99 to Alex via PayPal to get the app. I think this is a great way for smaller developers to get their apps out there, particularly when Apple decides to shut 'em down -- although they are sharply limited in the number of licenses they can distribute this way, no more than 100 devices total are allowed.