Running on the wall is one thing... but it would be too cool if it was possible to flip off it like Trinity does in M1.
According to Matrix Revisited, that was a hard scene - she kept missing the flip and got tangled up in the wires all the time. When she was practicing, she busted her ankle... So, they decided to do it in two takes
1) run on wall
2) flip off
instead of all one take. Interesting, huh?
-DM31