I tried so many email applications, but none could actually beat the productivity I operate my GMail account with the original web interface. My only gripe has been so far that I wasn't able to access my email when there was no internet connection. On the train to and from work, for example.

It's not that Google didn't have the tools to solve that problem. Google Gears is available quite some time and I use it extensively with Mindmeister.

Today I found on the official GMail blog that the Google engineers really are working on an offline mode for GMail. It's still work in progress and only available over the labs menu. This feature enables you to use GMail offline, and it also offers a "flaky connection mode" where it uses the local cache but tries to synchronize in the background.

Who needs a desktop application with internet connection when you can get the internet on your desktop?