Here at Ooyala we do a variation where you can propose your own 2-week project once per quarter, and as long as you get it approved by your team you can go do i

Here at Ooyala we do a variation where you can propose your own 2-week project once per quarter, and as long as you get it approved by your team you can go do it. You also do a demo. So it's sort of like what they do, but people individually schedule their own at random times, up to four times a year.