It has been discussed many times on the yahoo group MACCELLPHONE... I have the 555 card and it does not work with the MAC. (Not even with VPC). I use it with a small Sony I take with me most of the time just in case a client calls. I got tired of having to take two cars and having to leave in the middle of my son's events to handle a client's emergency. I guess someone will write some drivers after the prices drop a little more. http://groups.yahoo.com/group/maccellphone/?yguid=147505769 > It doesn't necessarily need a driver to be installed. It may work > out-of-the-box as a network device. A report that conclusively > confirmed or denied this (from someone who's tried and failed) would > be immensely helpful.