TetherBerry's name is fairly self explanatory. The software allows you to connect your BlackBerry to your computer to share your data connection with your PC. Until recently TetherBerry was only available for Windows, but now the app is going into a semi public beta for Mac users. You can head on over to the TetherBerry web site and sign up for an invite to the beta. You're not assured of getting an invite, but you might. Check it out.