Apimac has released Caller ID, a shareware application for Mac OS X that works in the background and provides a visual alert to inform you about the person currently calling on the phone. The tool lets you distinguish business from personal calls and lets you decide in advance how to answer and respond. It uses your Address Book contacts to match and identify phone numbers. To receive the caller ID information, you need a modem or a Bluetooth enabled mobile phone. You can also forward this information to other clients in your LAN. In addition, you can setup Caller ID to receive the caller ID connecting to another running copy of Caller ID in your LAN. There's also AppleScript integration so that when a phone call arrives it can trigger processes in other apps. The program is priced at $15.