I've been working on a cross platform mobile application for keeping track of how much time I spend doing things. Basically a consultants helper to make sure I'm spending appropriate amounts of time doing the things that move me forward and keep me aware of how much time I'm spending doing things that aren't going in the right direction.
Anyway, having done mobile web development and knowing the pain there, as well as having put together a few android/iOs "hello world" applications, I did NOT want to go down the "build 3 different versions" road. I understand that there are compelling reasons to do this, but there aren't compelling enough to do it (in my situation).
Knowing that there are a number of solutions in this space, I narrowed it down to things that seem to have #1 the most innovation and #2 the highest potential to NOT be a dead end career wise. My list was narrowed down to titanium mobile,rhomobile, and phonegap.
First off, titanium certainly has the best press corps in my opinion, the down side is that they appear to be going down the IBM path. That is, they're trying to build an "everything but the kitchen sink" heavyweight solution that is pretty off putting. In addition, the requirement to download proprietary development tools is just not where I want to go at this moment. While their solution looks very complete, I can't help but feeling it will end up being a dead end career wise. What I mean by this is that I think eventuall titanium will end up going the way of coldfusion - it will be widely used and very lucrative, but you'll be branded as a "titanium guy" for the rest of your career. For the reasons I mentioned, I actually downloaded the sdk, but didn't actually do any development using it.
Next is Rhomobile. One thing that excites me about Rhomobile AND phonegap is their distributed build system. This means I can actually build the cross platform components and NOT necessarily have the full SDK installed on my machine. Another upside to Rhomobile is that it uses ruby (a language I happen to like), but that upside quickly turns into a downside. I spent a number of hours trying to figure out how the browser components interacted with the ruby components and ultimately gave up. Rhomobile, I like the idea, but your solution is WAAAY too complicated and confusing. The other downside to Rhomobile is that same sort of "proprietary lock in" that I think will plague titanium. While I like the concept, I cannot get on board with rhomobile at this point.
Using phonegap in addition to ripple mobile emulator in chrome makes me super productive and I can use the development tools of my choosing. For now, phonegap + ripple + whatever text editor are my tools of choice and I highly recommend trying them out. As for rhomobile, guys... I'm rooting for you, but it's just too complicated and I don't have enough spare time to figure it out. Titanium.. I think you have a market in the corporate enterprise space, but you're likely to not attract many indie guys as you just seem tooo... heavy.