If you are a Google Apps user, you can access Google Talk for your domain by following these steps:
- Go to http://google.com/m/a/MYCOMPANY.ORG but replace [MYCOMPANY.ORG] with your domain.
- Tap the More tab.
- Tap the Talk icon to open Google Talk for your Apps account.
Tip: Bookmark the Google Apps Talk URL in Safari by tapping the + button.