Good analog to degital i2c devices...if your uC dosn't have enough a2d channels but has i2c interface it works as an easy fix.
I think they have some DAC but I've never had much use for them....
Look at any thing that is i2c or SPI interface....that's normaly the interface you will want to use for hobby robotics
when you buy parts (or sample) from a company like that.
A better Idea is to figure out what you need first though