Watch the Octaves! online guitar lesson by Angus Clark from 50 Radio Rock Licks You MUST Know
Big octaves were the order of the day for bands from Green Day to Blink 182, but don't forget Jimi used 'em too! So did Wes Montgomery apparently from what I've been told. You're creating a part here, nothing flashy. But it can really do the trick. Be careful to mute the strings you're not using.