Originally Posted by corporate-wage-slave

At HKG: You can physically do connections very quickly, 25 minutes or so, and you need to be at the BA gate 21 minutes before departure. There are three problems I foresee, if you are a mere 20 minutes late:
1) There's a good chance that the gates will be as far apart as is possible. Now HKG is well designed and you can get from one end to another in a matter of minutes, but it may lead to an unpleasant transfer, particularly if you don't know the airport. You have to clear security from the arrivals level to departure.
2) This is the last BA flight of the day.
3) You will need to get this booked on to one ticket if you want to protect the connection, so almost certainly a travel agent would be involved.

So if you are happy to risk it (I probably would be if one PNR throughout)