Some people get out of control with exaggerations these days, and sometimes you need perspective — the exact perspective! Pective is a website which simply shows you the actual size of things. Just tell it what size screen or monitor you're looking at, and it will adjust accordingly.
Maybe you have freakishly small hands and want to see how the G1 would look in them. There are a million practical and fun reasons, including comparing things in your hand with real-life things you may not have on hand, like the $10 bill pictured, which is obviously not actual size in my picture, so go check it out yourself!