Protecting Confidentiality in the Evaluation Process?

A recent question from a public procurement professional: 

During the evaluation process do you allow your evaluation committee members to take the proposals home with them, or away from the office to read, prior to getting the entire evaluation panel together to discuss?  If so, 1) do you find that the members do the necessary ready prior to meeting; 2) do you have the panel members sign a confidentiality agreement or something similar; 3) do you believe this process protects the confidentiality of the RFP process?

Have you ever sequestered your evaluation panel and required them to read the proposals together in one room at a set time?

Which method do you prefer or do you find works best?