Daniel Radcliffe mentions Tom in a recent interview with WIZARDUNIVERSE:
In the future, when you look back at the making of the six films, what do you think might stick in your mind about the process?
RADCLIFFE: Michael Gambon, when we were doing all these sequences together, would come up with abbreviations for the shots. None of which I can actually repeat because they're all quite offensive, but they're very, very funny. Some of them have actually stuck on the Potter set.
One of the sequences, on this last film, was with Tom Felton as Malfoy in the bathroom. Me and Tom have always liked each other but we actually started getting on really, really well in the last film, so that will be one of the binding memories.
You can read the entire interview here.