Resistance bands are great tools for toning and strengthening without the use of heavy weights. This workout has 6 upper body exercises using resistance bands: http://www.fitnessmagazine.com/workout/arms/exercises/toned-arms-shoulders-moves/
You can also check out this page for total-body workouts using resistance bands: http://www.fitnessmagazine.com/workout/equipment/resistance-band-exercises/