You already know what i'm gonna say, but - squat. it'll also give your ass some lift/perk.
http://www.exrx.net/WeightExercises/...s/BBSquat.html
if you use a standard bar, that's 22.5 lbs, olympic bars are 45 lbs. 90-year old men can usually pull off a set of squats with just the bar, so i see no reason why you couldn't do it too.
squat form is kinda complex (given that it's a compound exercise) and unforgiving, but i can go fish out some resources if you're interested.
i do squats and calf raises, personally.