I'm not sure whether it works with Realtime or not, but I have captured other streaming video using Camtasia.
I think Frontcam does it too. FrontCam has a demo version
http://www.frontcam.com/fcsetup.exe which I think would work OK - but you'd need to check that it's not disabled in some way.
There is a demo version of Camtasia which I think would also work fine. Its available at
http://www.techsmith.com/freetrials.asp
Its fully functional for 30 days - which should do the trick for you.