If you have no weights take a can of beans (or anything you may have) in each hand and lift them while you watch your favourite show.
This not only burns calories but will noticeably start to change the shape of your body even if you only manage 5 or 10 minutes per day.
Or put your trainers on and jog on the spot when the ads come on - short bursts like this will add up and make a real difference to your efforts.
Excellent for people like me who usually view excercise as a bit of a chore!
Any step towards slimmer, sexier arms has to be a winner.