Gmail's just released a new mobile version of its Java application: version 1.5. The major new feature is the new menu option for easier access to your contacts along with contact info (photo, email address, etc.). If you have a phone number saved with a contact's details, then you now have the ability to call them directly from Gmail. This may be the only good, new feature for Gmail mobile version 1.5, as there appears to be drawbacks for every other feature that's been added.
You can also save messages to be sent for later, but this tool is still somewhat limited by the fact that the saved message will not go to your Drafts folder, and you can only save one unfinished message at a time. A couple of other new features let you see the bandwidth for every time the app loads data, and also an option for encrypting your data. Google has noted that this will slow the application, and is not recommended.