How to Accept a Group Invite on a BlackBerry
- 1). Press the "Menu" key on the BlackBerry and click the "Instant Messaging" icon.
- 2). Click "BlackBerry Messenger" to access the application.
- 3). Select "BlackBerry Groups" to expand the field and view all group invites.
- 4). Click on a group invite, then click "Confirm" to add the group to your BlackBerry.
Source...