Thanks mikeyfly - I should have mentioned that i'd done a quick check, but couldn't see anything for T7, where i'll be leaving from on the BA flight to LHR. Is it possible then to come off the AA flight in T8, put stuff in the luggage locker in T8 and then head off, coming back to T8 to collect before going across to T7? I can see it's noted as arrivals, so is that landside (i.e. i wont have to go back through security just to come back in and collect the bag?). I saw that BA have lockers in the lounge since the refurb, but these were noted as being unavailable due to TSA regulations, so wasn't sure if there was anything "free" within the lounge. That said, i'm happy to pay $18 worst case for a few hours if it means i can get into the city with just my rucksack.