I only sprint once a week but I play competitive level racquetball 2-3 times a week.
Racquetball consists of many very short and reactionary "sprints".
Ultimate frisbee and touch footy are team sports I play in for sprints I don't notice.
As others have said, sprinting is very common in sports & in play (which count equally IMO to more "formal" sprinting) so I probably sprint almost every day of the week in some form or another.
I think I need to engage more in the playing aspect of fitness. I'm doing my 3rd sprint of the week tomorrow, but I'm trying to peel myself away from routine that I seem to be slipping back into. Sprints are hard! I thought I could pull it off having run long distances in my past...but no...much more challenging. Out of breathe by my 5 of 8 on the track. Hopefully I start to see some results sooner than later. Slimming down the right way seems to take forever, unless my body is trying to tell me it likes where it is. Bleh.
Zilog - I agree.