There are London Sightseeing Tour buses
http://www.theoriginaltour.com/ but
I dont think they run at night.
However you could buy a One Day Travelcard at Heathrow Underground Station
(£5.40) and take the underground up to Central London. You could travel
round the centre on the normal buses and either take a late Underground
train or the N9 Night Bus back to Heathrow.
The web sites
http://www.tfl.gov.uk and
http://www.londonbusroutes.net give
you more info about public transport in London.
"Gazeta" wrote in message
...
Thank you for invaluable opinions
There are some reviews of trying to sleep in Heathrow he
http://www.sleepinginairports.net/eu...onheathrow.htm
they don`t sound very optimistic 
anyway, I have no choice, I have early morning flight to USA,
I`m arriving in the eveining previous day and not having money
for expensive hotel, I will stay at the airport.
... I know, I know, I am going to be bloody exhausted 
I don't think they let you sleep in the airport after it closes at about
midnight
As far as I know the airport is all night opened..
Once again I will ask, how should I arrange night sightseeing tour
in Londyn? I`m not affraid of being lost in the city because I don`t plan
to wander far away from the main city attractions full of helpful people

p.s The baggage will already be checked and sent.
Thanks in advance for valuable advices