Marshall - 9:04 pm on Mar 2, 2012 (gmt 0)
Under Privacy Settings, click on 'Edit Settings' next to How You Connect. It will give you choices for:
Who can look up your profile by name or contact info?
Who can send you friend requests?
Who can send you Facebook messages?
Who can post on your Wall? and
Who can see Wall posts by others on your profile? (Note: Stories about likes, friendships, and some other types of wall content aren't included in these settings.)
Uses the drop down menu to the right of each of the above to select who can do what.