Do you have a favorite iPhone dialing app? Did it stop working after you updated your iPhone to OS 3.0 last week? If so, you might want to read Kevin Bomberry's thoughtful analysis of the technical issue and the situation it has caused for developers in his blog item...

Making calls from within your iPhone app - iPhone OS 3.0 breaks existing paradigm

It seems that Apple's iPhone OS 3.0 changed the way how opening a special URL string used to dial phone numbers from within 3rd party apps works. This change pops up an alert box before a phone number can be dialed from a 3rd party app. This makes perfect sense from the point of view of protecting the iPhone user from rogue dialers and other related problems. But, unfortunately, it breaks a lot of legitimate iPhone dialer apps.

So, what do you think? Is this a security feature for the end-user or a bug that needs to be fixed?