There is really no way of connecting a webcam to a serializer. My first thing would be to check to see if a CMU type camera will pick up IR. If so then maybe you can find a filter that will block out most of the visible spectrum and only let through IR. I think a blank piece of developed negative from a camera store will work for this. Then you can use the built in  CMU cam functions to do the tracking. Unfortunately at this time there is no way to talk to a CMU cam with the serializer. we are planning on adding that functionality in the future, but it is 6-12 months away at this point.

If you are not stuck on using a camera, then I would find out if the beacons are modulated. If they are modulated at 40khz or any other popular freq then you can use a pair of standard IR detectors with a blinder in the middle to find the beacon. These can be easily connected to the serializer.  If they are not modulated then it will be much tougher because the Sun, lights, everything gives off enough IR to make it tough. 

Ringo