Just switched to drop bars from cruiser upright!
 

Well, for a while now I've been commuting in a cruiser fasion - low sprung saddle, big wide cruiser handlebars... single speed... and my knee was killing me... so this weekend I decided to get a Technomic stem and throw a bell lap bar on the bike and put on some old toe strapped pedals I had. I don't think I have the fit quite right, but still - WOW - the last time I used a drop bar it was way too low, now I have this one at or just a little above saddle height and I have cross levers on it as well. Its wonderful! Grasping the tops is comfortable and in the drops is comfortable generally - but it feels a little overstretched (just about no bend in the elbows) on the hoods (and sometimes my left hand feels a little hinky, but then it always has)... so I'm thinking of going back about 10mm on the stem - looking at the dirt drop stem from nitto (just for aesthetics really). Though what's got me confused is that it feels like I'm trying to push myself back in the saddle sometimes - I'll adjust the tilt - its already pushed back as far as it goes, but maybe I'll tilt the nose up a touch ... Anyway - thought I'd share my new experience. Now I just need to finish the 3 spd wheel for it and respace the frame a touch. Anyway - drop bars!

Maybe your saddle is too layed back. If you shift more weight onto your hands, you find them easier to use.