real time remote testing

I am currently dong some work on a web portal.
I am wondering if you have any recommendations on tools for conducting real time remote usability sessions. I am imagining the following:
The user is at home exploring a web site and an overlay appears asking if they are interested in trying to qualify to participate in a usability study and receive a gift certifcate for Amazon.com "_blank" for example.
The user then clicks and is directed to a brief online survey screener and it says we will contact them in the next 30 minutes if they qualify. Meanwhile I am in the lab monitoring survey response to see who qualifies.
Next I would call them and and we would initiate some method for them to be able to share their screen with me and continue communicating via voice over the phone.

I am beginning to look at some applications such as
Ethnio Beta: boltpeters.com/ethnio "_blank"
Glance: glance.net "_blank"
Breeze: macromedia.com/breeze "_blank"
CoPilot copilot.com "_blank"
and WebEx.

My friend Stan Caplan recommended I check in with you to see if you are aware of some well known solution that is currently commonly used in the usability community to conduct real time remote web testing.

If you or the technical group have some thoughts on this matter, please fire away. Please feel free to forward thisquestion to the TG.

regards,
doug
dbram@gmail.com
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