My role on the Lync team focuses on "gadgets for Lync", I manage the relationship with our audio and video device partners, and one of the things I like about working on this team is our focus on improving the customer experience. One question we get asked on occasion is what devices have been qualified/certified to work for Mac. The short answer is that we don't yet qualify devices for Communicator for Mac 2011 or the upcoming Lync for Mac 2011 clients, but most of our device manufacturers have good solutions that will work with the Mac clients. USB devices such as headsets and speakerphones are excellent alternatives to basic computer microphones and speakers.
For example, Plantronics recommends all of their USB solutions that are certified by Microsoft (Calisto, Blackwire, Savi, and Voyager families), Jabra also recommends all their Optimized for Lync portfolio for a basic experience with Communicator for Mac 2011 and Lync for Mac 2011.