Update -
Last year during an office meeting at my previous brokerage, I shared an example of a sign-in sheet I had designed. I originally posted it here, protected by a password, and have since decided to remove the password protection.  Hey, if it can help out another agent, I am good with that!

Here it is available in a few different formats if anyone wants to use it.  I am sure it could use some improvements/changes/localization/etc.

Feel free to use it, edit it, and make it better.  If you do, let me know and I can post your version too.

File Download:
Excel – Open House Sign-in Sheet
PDF – Open House Sign-in Sheet

Google Docs Link:
https://docs.google.com/spreadsheet/ccc?key=0Amv1LXXslLXZdHQ5QU5MWGQ3Z0VfWlRDNFVBWl9NOFE