If you’ve decided to deliver your app via the Web, you should
embrace the capabilities and constraints of the Web. Don’t spend
time and resources making a pretender app, spend that time making
a great app that works on the Web.
Villamor cites Bagcheck as an example of a mobile web app that embraces its webbiness and doesn’t pretend to be a native iPhone app. I’d cite 37signals’s mobile version of Basecamp as another. Basecamp maybe veers closer to the pretending-to-be-a-native-app line, but it doesn’t cross it. I like the mobile version of Basecamp more than the “full” version.