H.323

My company is getting heavily engaged with corporate video conferencing and looking to build out our infrastructure. In looking into this a bit, it seems that close to half of us already have MacBook Pro's with built-in iSight cameras. Is there any solution on the market, whether from Apple or 3rd party, to allow us to join a video conference from our MBP's when the conference is hosted on a more traditional corporate "room" solution like a Polycom or Tandberg? I understand that those systems use standard H.323 technology allowing for some amount of interchange.

It'd be a shame if the Macs couldn't be used to join in.

What can we do to build some amount of interoperability?

Thanks
Marc Mandel