According to the New York Times, Google is now developing an iPhone Web app for its Google Voice service, which had its iPhone app famously rejected by Apple for inclusion in the iPhone App Store in July.
However, Google isn't going to wait for the FCC to slap Apple's hand and make it include the Google Voice widget in the App Store. Instead, Google is doing the next logical thing and just taking all of the functionality from its rebuffed iPhone app and turning it an iPhone Web app.
This might actually serve to throw more attention on iPhone Web apps in general, since these Web pages look and feel much native iPhone apps (you can even add icons for them to the iPhone screen) except that they open in the mobile Safari browser.
The biggest drawback to doing apps this way is that the performance can be slower than a native app. But, these apps are also far easier to port to other touchscreen platforms such as Palm Pre, BlackBerry Storm, and Google Android.