The Number One Developer Productivity Tool
Cal Evans at php|architect – The Number One Developer Productivity Tool:
"If you require your developers to work onsite, the number one productivity tool you provide for them is a door that closes (well, 4 walls and a ceiling to go with it). Given control of their environment, developers can reach their peak productivity most days and sustain it. Without control, most developers will have a hard time even getting close to their peak."