Originally Posted by
Frozentech
Yes they do, indirectly. Click the flight number, and it will pop-up a window with the flight details including mileage. It's per flight though, so you have to add up the miles for each segment to get the total. Note that you have to actually click the flight #, during selection/booking, if you just mouse-over, it shows less detail, only departure/arrival times and total duration of the flight.
This is how I do it for
most flts but sometimes that info is simply missing, and not just for <500 mi. That's when I check out FlyerStats, a free iPhone app. It is a nuisance but it works.