GPush is an incredible app. No, I've not yet had a chance to use it yet and I don't know if I want to just yet. It's probably because it isn't more than a notification app for Gmail.
I want more. Early, I had wondered whether push notification can be enabled somehow through Safari. Well, that's a question for iPhone 4.0 or later. The reason I asked about that is because Google is working on getting Google Voice to work through Safari after ATT, maybe Apple, rejected it and pulled out 3rd party apps that supported Google Voice.
Google Voice alerts you via Gmail when you get a voice mail. However, it doesn't do that for SMS yet. I'm guess it's at the request of wireless providers looking to protect their lucrative stream of revenue.
Now, maybe there is a workaround. GPush is a good example and I'm hoping other means may be possible in the future (Growler, please do something). According to the GPush developer, it provides notification only. It doesn't serve to launch the mail app or open up the Safari to point to Gmail.
In any case, Maybe Google or a 3rd party developer can create a push notification app for text messages received by Google Voice. But that may not be necessary if Google enables Gmail notification for SMS.
I guess what I'm saying is that there is hope. I don't see how Apple can not allow apps that simply serve as messengers. Maybe that is Google's plan. Create notifications for texts being received by Google Voice and the user will have to go into Safari to retrieve the message.
Note: Did GPush get pulled? I just tried buying it on the iTunes store in the US and it's not available. Nicely played. FCC, your move.