Thanks everyone for your replies. There is definitely no standard. During lunch today, I saw a Lufthansa (wheels up), a United (wheels down), a Continental (wheels up), and an Alaska (wheels up). No rhyme or reason.

Well, yes and no.

You're correct that there's no 'standard' as you perceive it because it all depends on the airline, type of aircraft, their procedures, etc... - things you (and many of us) are not familiar with.

Yes, there's a reason though: it's their procedure, the airplanes slow down better with gear down, lower risk of ice falling off if you drop it too late etc, etc. So yes, there's definitely a reason...

In the AF heavy world we used to drop gear on our vector to base for radar patterns and at midfield downwind for visuals. Now we are more in line with the airlines and drop them just prior to the OM or even a bit later. Fuel savings, of course.

dot and a half, gear down flaps 15. well at least in blue tail land...