What is the most efficient way to port an iPhone app to Android? I know Apple doesn't like 3rd-party, non-Objective C platforms generating code for their platform ... but is there something out there that can take an iPhone app and convert it to Android friendly code?
If not, how have folks out there been creating Android versions of their existing iPhone apps?
There's nothing of the sort to port your app. You can use 3rd party tools to create apps that work in both. That's what Titanium and PhoneGap were aiming at. With the new changes to the SDK Agreement, those look like they're not really "legal" or at least violate the agreement.
As for your other question, yes, people do create 2 separate apps. One for Android and one for iPhone. That's the way I currently do it and seems as if Facebook and others do the same.
Yeah, people don't usually love the answer that we have for this one at Appiction. It seems like it should be easy since they are so similar, but they are completely different operating systems with different ways of being used. Sometimes a company will be able to cut a deal with you since the art has already be developed and the basic wireframes have been conceived. At Appiction we created a video to answer this exact question for our clients: http://www.youtube.com/watch?v=Y-fdRw1WNYI