There are several options, including any Whammy (won't do both at once, though), the Eventide Pitchfactor, the EHX HOG, POG, and MicroPOG, and my personal choice, the FoxRox Octron.
To my knowledge, the FoxRox is the only analog pedal that will do Oct Up and Down at the same time. Typically I would likely promote a digital octave, purely for the improvements in tracking (I should note that I never use octaves without distortion, so the infamous digital tone gets blanketed). However, the FoxRox tracks pretty well, and I find that while I don't hate the tone of the digital octave up, I LOVE the tone of analog. It gets a really nice distortion that's just enough for my tastes, so I blend in just a little to give a nice upper register grind to my tone when I go for that super heavy octave down tone.