i was watching a few vids on youtube last week - i think they were called ghetto workout or something like that
found the vid:
http://www.youtube.com/watch?v=kDCxH88-9X8 and there are lots more like that
pullups, chin-ups, dips, pushups - flat and decline, leg-raises, planks, one legged squats and you can get a crazy pump in many muscles just from flexing over and over
also if you have time to shop or order them you can get those resistance bands:
http://www.youtube.com/watch?v=wzyCtzAF8F0 or easily make your own out of bungie chords which come in all kinds of thicknesses which you can combine or link for infinite combinations
since you mentioned an emphasis on legs - in addition to one-legged squats (fill a back-pack with water for increased resistance - of course put the water in something! lol) you can do stiff-legged deadlifts for a crazy ham workout - especially if you stand on a step so the weight is lower than your feet - just need to find something heavy and figure out a way to lift it - rope or something like that - there's another workout i just saw in muscle and fitness for hams that i think just requires a short pole (sturdy stick?) here's a vid called ham killers -you could even do this on the floor with your feet under a bed or something:
http://youtu.be/K0o-3Ii3Blc