UPDATE 2: GPush's developers posted in the comments with the following info:
On Saturday August 8, 2009 GPush made it into the App store. We are currently experiencing a server issue and have temporarily pulled the app from the store while we work on the problem. This is an issue with our servers not the application and we will not need to go through the approval process again. If you have already downloaded the application, please know we are working to resolve the issue as soon as possible.
UPDATE: According to the developers on Twitter:
GPush made it to the App Store, we are aware of a server issue & we temporarily pulled the App off the store while we work on the servers
ORIGINAL: GPush [$0.99 - iTunes link] provides a work-around for Gmail push notifications for iPhone 3.0 users. GPush is not an email client in its own right; it serves only to notify a user via sound/vibrate, text alert pop-up, and/or numerical badge, but the user still has to manually launch the iPhone's built-in Mail app to actually download and interact with the email.
We've only had a chance to try it very briefly, but it worked well, notifying us incoming GMail messages very quickly. Job. Done.
Unlike Boxcar, for example, which provides similar intermediary push notification for Twitter clients, GPush doesn't have the option to automatically launch Mail when you get an alert (only an "okay" button, not a "view" button). We also couldn't get it to work with Google Accounts, the paid version of Gmail that uses custom domain names. (GPush makes no mention of Google Accounts support, but if it occurred to us to try it, we figured it would occur to readers as well).
Lastly, GPush keeps asking to know our location. Why does it need that information? (Update: per the developes
All in all, GPush does exactly what it claims to -- it provides near instant notification for Gmail for iPhone users. Until Google adds Gmail to Google Sync, or Apple and Google get off their duffs and build IMAP IDLE into the Mail App proper, if you want "push" Gmail on your iPhone, check out GPush and let us know what you think.
More pics after the break!
[Thanks John-Fox for the tip!]