Bluetree - I spoke with Polar at Interbike this year regarding their Mac compatibility. They report they are working on it; however, they weren't able to give out a time frame. I just use an excel spreadsheet to record all of my data. I know it would be nice to use the HRM as it is supposed to be used, but you can still record the data manually. Contacting Polar as crazycanuck suggested is a good idea. I often tell customers to contact the companies directly. These companies often respond quicker to customer suggestions as opposed to industry suggestions.