Let's just do a pro and con for the Mobile Web-based Application. iPhone apparenty leans toward this model, where as the MobilePC leans toward the rich app model. The one example I've seen of the Mobile app model is found here http://www.visitmix.com/Blogs/Joshua/leaflets-for-iphone-beautiful-standards-based-design/

Called "leaflets" this dev shop renders small html-based applets that deliver just enough data to be useful, formatted to fit the iPhone screen. Now I can see where social-content based services could be used here; deli.cio.us is a useful tool to have on the mobile device.

So lets hear your opinion on this mobile web app model.

Pros

1. Lightweight apps can run and deliver data anywhere on any mobile device
2. No need to reinstall if the device is wiped out or new
3. Common theme, or customizable themes
4. Can be used on any device with internet web access

Cons

1. If the network is offline, so is your app.
2. Minimal user interface capabilities
3. Must ensure applet runs in different browsers as not all follow "standards"
4. Could be hard to configure for the average user

As a proving ground for this concept, i've come up with mobile web app located at http://mobiletools.robkennedy.com/

Right now, I'm discovering what is wrong with the Mobile 5.0 IE browser (can't figure out partial paths, asp:ImageButton's dont appear to work, and style sheet rendering issues) I'm going to try Opera Mobile and see how it does, but through the Windows browser it does well.