iPhone development frameworks

[ParanorMAC]

Has anyone explored the various iPhone development frameworks available and what are your experiences and recomendations?

Here is a list of a few I've run across:

• PhoneGap
• iUi
• jQTouch
• iWebkit
• Magic Framework
• QuickConnect
• LiquidGear iPhone
• Appcelerator Titanium

iPhone Web Apps vs. Native Apps?