Paul has some VERY good information on his site. Information about how to do this or that and information on using magnetic building tables. Paul has an article on his site about MY building table which has proven to be THE MOST VALUABLE TOOL that I have.... Take a look

[link=http://airfieldmodels.com/information_source/how_to_articles_for_model_builders/tools/magnetic_building_board/jeff_cottrell.htm]Magnetic building table[/link]

Pins can easily be pulled out or moved. With this system that I have, you're gonna break something before you move it accidentally.