As Administrator can I view another users visibility of things

Hi,

I am creating a mashup to help me with my development (particularly security). So far on my mashup I have a list of users, and can show the groups of which they are members when a user is selected. What I would also like to do is show a list of the things that are visible to that user. The idea is that I can quickly view which things are visible to a selected user.

Is there a way that I can mimic another user when calling services such as GetImplementingThingsWithData(), so that I only see the things which are visible to them. Alternatively can I do this at the group level, that way I could iterate through a selected user's groups.

Thanks,

Kieron