User Story Execution Process

• Select (story | task) from story wall
• Move task card to "In Progress" column
• Model code that needs to be written (use object model and sequence diagrams)
• Create technical tasks needed for completion
• Get team member to review design
• Mark each technical task as "pair" or "single"
• Test-drive code to completion according to design.  Commit changes along the way to enable concurrent development.

I will leave this without commentary for now, except that: it is working quite well.