if those are your style then check these out:
Body Weight Suspension Strength Building Equipment, Weightless Abdominal Fitness Training Apparatus, Universal Strength Apparatus
they are very simple but very versatile. i use them for everything from push ups to dips to pull ups. and because your arm can move around anywhere it is amazing for all those little support muscles. when i first saw them i thought "great idea but they won't make that much of a difference really". then my mom bought my dad a set for christmas and man did i change my mind. again its nothing advanced or cutting edge, it simply allows you to perform exercises without any help.