A friend of mine, CTO at Elfo [1] (a 60-ppl Italian software basically-unknown company) is successfully using Kanban for software development since almost 2 years.

Each team/project (6 to 10 developers) has it's own Kanban board, each person has no more than 1-2 tasks/phase and they focus on keeping the phases balanced, i.e. with the same amount of tasks. They're happy since its a light weight way to have a full picture of what's going on.

His original notes (in Italian, sorry) [2].

[1] http://www.elfo.net [2] http://www.robertocappelletti.com/2012/01/kanban/