You can use OggChat right from your iPhone with the BeeJive or IM+ applications.  Here are the steps for adding a Google Talk account in BeeJive for iPhone

1. Once you launch the BeeJive application, select Accounts
2. Click the + button to add an account
3. Select "Google Talk"
4. Enter your Gmail address and password.  Hosted accounts work as well.
5. Change your status to Available.
6. If you've included the OggChat Widget code on your website, you're ready to chat.
7. If you don't see chat1, chat2, and chat3, in your contact list, you can re-send invitations by logging into OggChat, selecting your operator, and choosing "Re-Send Chat Invitations".