IR Object Detection

Anyone know much about simple IR detection? I'm trying to decide which way to go for a simple PIC Micro controlled robot; either medium frequency pulsed detection or some sort of rapid on/off comparator. If I use frequency modulated is there some sort of optimal frequency? 38-40kHz seems pretty common, but I've got a bit of flexibility here.

None of that actually exists you're just making it up to sound smart.

>>1
Well don't be different just for the sake of being different. Unless you've got a good reason to use another frequency, stick with 40kHz. More pre-built hardware for you to use.

what does your robot do? it collects data about the surrounding environment, then discards it and drives into walls?

>>4
understands robotics.

>>4
less driving into walls, more firing lasers randomly and making irritating noises.

also I felt a six legged walker would better facilitate my autonomous wall-humping needs.