The PhoneGap

     PhoneGap, Titanium are designed as a platform independent developing solution.

     Both of them are using the framework of HTML+CSS+Javascript.

     It should be a solution, But should be not a useful solution. First, it depend on the HTML5. 

     Secondly, the performance of the solution will be bottleneck forever, It deemed to be impossible to implement high perfomance application by PhoneCap.

     Using HTML+CSS+Javascript to implement platform independenc shoul just be a buitiful dream in current stage.

    

     On the other hand, Rhodes use Ruby+Rails as a solution, It should be better than PhoneGap, because the app code is most like native code, but there have a Web APP server between app and real server, the performance is also a tough issue.