Which framework would you choose to validate forms in a jQuery Mobile app? 
In addition my webapp runs in the PhoneGap native wrapper on iPhone and Android.

There are numerous jQuery form validation frameworks out there - but from your experience what works well with the mobile version of jQuery?

Criteria that would be interesting in the mobile context:

* touch-enabled notification messages - in case of wrong validation the message is ideally optimized for small screen estate
* message in place with the wrong form field
* offline functionality - since the PhoneGap app runs occasionally without network access