Not to put too fine a point on it. . . I have no problem getting webcams to work on a Mac at decent resolutions, but I am specifically looking for a webcam that sends and receives 720p in applications that support 720p. I have yet to see a webcam that purports to be an HD webcam for the Mac that actually utilizes 720p in applications such as Skype or Facetime or others. The latest version of Facetime supports widescreen 720p, but I would wager that your HD camera would still default to VGA mode, David. Bria softphone also supports 720p, but I have yet to see an HD Mac camera that will actually send HD video.
iChat and PhotoBooth do not support anything greater than VGA, so they don't really apply to my query.
Well according to Skype's website, only Skype for Windows supports 720p HD video calling. So no webcam on Mac, be it HD or not will support Skype HD video calling on Mac until Skype supports it on the Mac.
Culled from Skype.com: http://www.skype.com/intl/en-us/features/allfeatures/video-call/
*The latest version of Skype offers the clearest, crispest, sharpest quality video calling, and High Definition capability. If everyone on the call has an HD quality webcam, you can see the video in High Definition.*
*What you’ll need:*
** _The latest version of Skype for Windows_*
** An HD quality webcam*
*A dual core processor, and a fast internet connection of 512 kbit/s or more is required.*
Here's a blog post I wrote recently about how to hack at Skype a bit to get 720 resolution on a Mac.
I've used this process with my new Macbook Pro's Facetime HD camera as well as with an iMac and a high end conference room camera through a video capture device. It seems to work fine if you're willing to live with an older version of Skype until they get off their &^# and support HD.