On the other hand, "strafing" has something to do with moving sideways, according to Google (="sivuttaisliikkeeseen")... Another dictionary says "strafing" means certain kind of combat aeroplane (maataistelukone?). I'm confused now...
I suspect the gaming terms probably come from the way ground attack aircraft fly past or around their targets while shooting.
Aircraft with side mounted guns fly one way while shooting another (if you take the gunners view, it's like sidestepping in an FPS).
There's a manoeuvre called a "pylon turn" that works exactly like circle strafing in an FPS, especially when done by a helicopter gunship.
P.S. Wow, I'm bored today :P
Edit: I learned stuff like analytical & logical thinking, lots of obscure words and not to stand in the fire.