Watch the The I-IV-V Power Chords online guitar lesson by Ravi from Guitar Lab: 30 Rock & Pop Progressions
Rock, blues, and boogie grooves often employ a power chord fingering and letting your pinky do a little extra work! Try this variation of a I-IV-V progression on for size, Chuck Berry, look out! Make sure you only play the two strings that you are fingering, this is really how to capture the blues/rock feel. You can also play these chords in the open position, further reducing the amount of effort.
Examples: Roll Over Beethoven, Johnny B. Goode, Run Run Rudolph, Hound Dog, Hard to Handle, House is Rockin, Before You Accuse Me