I just flew a few weeks ago, and the stewardess said it would be OK. I think that if the plane's not too crowded, and you ask politely, there wouldn't be any problem. Of course, if it is crowded and people are still boarding, I can see how there might be problems.
I think that the key is to be polite. While airline service has pretty much gone down the tubes over the years, many of these flight attendants have to deal with grumpy, rude passengers, and tend to get grumpy and rude themselves. They seem to appreciate a polite passenger.
BTW, if you want great service and a very comfortable flight, try flying Midwest Airlines. It's by far my favorite airline to fly. It's a bit more expensive, but worth every penny.
Mark
I used to think that politness worked..but sadly..it doesn't...FA's today have it tough...and they're so overworked and overstressed that there isn't time for "kindness" to work its normal magic.. Second, if you're nice, many assume you're just trying to hit on them..
I agree, Midwest may be the best kept secret in the air and those baked in flight cookies are scrumptious.