I flew BA to Orlando from LGW two weekends ago and BA have used bits of wood to modify their cabin-baggage-size-checking-things which are dotted around the checkin area so you can see if you can squeeze your carry-on in to those.
I'd highly recommend checking in online as the checkin queues were huge - the bag drop queues were much smaller.
On the day I was there it seemed that handbags were causing many of the delays because the "one piece of carry on" was being strictly enforced - many women desparately trying to shoehorn their handbags into their handluggage etc.
Cellphones, cameras etc. were all OK you just had to switch them on and show they worked.
Incidentally security was equally as tight at Kennedy Space Center Visitors Center...