I sometimes think about what the trade-offs are in making Texags a super badass HTML5 mobile-ready site as opposed to a native app. The one I can think of that you really give up is push notifications for events, such as PMs.

So why not offer an option for email notification for PMs? Almost everyone already has that built into their phone OS and it will basically mimic this. I went to my Account page just to make sure and there is no option for it.

You could even offer a daily digest or individual message notification. Emails would contain a link to the PM, so the flow would be someone sends a PM, texags generates an email, recipient sees notification, opens email, taps link and is brought to the PM.