You should look at target audiences. Audiencing allows you to define audiences and then limit the display of certain webparts or content to certain audiences. A great introductionary article is located at http://office.microsoft.com/en-us/sharepointserver/HA101690531033.aspx
http://furuknap.blogspot.com/My SharePoint blog with articles, reviews, and code samples. Anonymized questions and answers may be posted to my blog.
http://www.understandingsharepoint.com/userexperience/Blog for my new developer book on the SharePoint User Experience
If, after a few days, I have not responded to a thread in which you have requested my assistance, please let me know by email furuknap<[at]>gmail.com. I am not ignoring you but I do get 20-30 requests each day and some responses might be lost.