Push ups aren't just for your chest you know.
If you do them right
and by right, I mean, maintaining rigid posture
(ie: no butt sticking up in the air or wobbling or drooping)
it is much a much better body tension workout than pull ups could ever be.
Just by arching or slumping your back slightly you could work out a different part of your chest.
there's several ways to change ye olde standarde pushe up
First
Put yer feet up on something, like a coffee table or a chair, so that more of your weight is on your hands and you get a better upper chest workout
or
meet your hands in the middle, forming a diamond with the forefingers and thumbs. works yer arms different - more tricep less chest/shoulder. If you're wearing a necklace/pendant you can try to make it land in the diamond every time for extra pump
or
spread the hands out past shoulder width, to increase definition between them man boobs, the middle of your chest
if you really want to do it hard
Put your feet on a table and your hands on two chairs just shoulder width apart. When you go down, lower your chest past your hands. Bet you'll do less of those.
Turning your elbows outward works your upper chest and shoulders more while pinning them to your sides works the lower chest
Place your hands lower and higher wrt to your shoulders (ie: either at/above head height vs at/below nipple height) to adjust the amount of body tension required
There's clapping pushups like dood said earlier
But, if you want a body tension workout (climbing, climbing climbing)
Try to hop your full body up and "clap" both your hands and feet
so
um
yeah
I like pushups