feedback - Mockup review process

Possible Duplicate:
How can we improve the internal wireframe review?

I am trying to understand what the best practices are for

1. sharing mockups with clients online and


2. capturing feedback on the mockup from them

Ideally, I would prefer to have them comment/provider their input on the mockup screens. Better yet, it would be great if I can collaborative participate in the session.

I request your input on the process you use and works for you.