My supervisor at work just switched to VoIP at his home, and he enjoys telling me about all the fun he's having with his new toy. I've been hesitant about the whole thing (read: old dog + new trick), but this article referenced at The VOIP Weblog has me intrigued.
In an article for Macworld Magazine, author Ted Wallingford (also of VOIP Weblog fame) compares Phone Valet 3 and Phlink in a head-to-head showdown. Each ships with a USB dongle for connecting your Mac to a phone line, though Phone Valet requires the use of an additional adapter if you want your computer and phone to share the same physical line. They handle contact management quite differently, too. While Ted found Phone Valet's built in contact manager to be "...rather cumbersome," he was pleased to see that Phlink simply uses Apple's Address Book.
Aside from that, each offers all sorts of fun scripting options, customizable ring tones, call logging, voicemail and so on. The overall winner? Phone Valet, for its multiple mailboxes and highly configurable message recorder. Read the full article here.