There are some short twisted JR11 cables you can buy to run from face plate to modem, these replace the 3 foot cheap JR11 cables the modem's normally come with. One of the broadband forums people were using and conclusion was they gave a minor speed improvements.
Another thing considered worth doing is connecting the modem via a mains AV filter. The theory here is there could be electric noise that could upset a modem, say a pulse from a washing machine motor, or interference from network over mains adapters.
If your chasing all possible speed and stability the things above are probably worth considering.