Below you can see the front view size comparison of Olympus E-P2 and Olympus E-P1.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Olympus E-P2 and Olympus E-P2 have exactly the same weight.
Also keep in mind that body weight is not the only deciding factor when comparing two interchangeable camera bodies, you have to also take into account the lenses that you will be using with these bodies. Since both Olympus E-P2 and Olympus E-P1 have the same Four Thirds sized sensor, their lenses for a similar focal length and aperture will be similar in size and weight.