Apple hasn’t added push for Gmail to its Mail app on the iPhone, but Google has worked around that via Google Sync. All you have to do is set it up as a Microsoft Exchange account. At last!
iTwitter had push notifications for mentions and direct messages, but only from other iTwitter users. iTweetReply supposedly works for any mentions or DMs. Not the prettiest or most feature-packed, it’s $US2 if you’re dying for Twitter push. [iTunes]
Best non-IM use of iPhone 3.0’s push notifications yet: Prowl is a $US3 app that pushes Growl notifications from your Mac to your phone. Growl‘s a global notifier that plugs into everything from BitTorrent apps to iTunes to Mail.