Wait... just explaining...
People that are in appear offline can nudge people that isin't offline. The same is for online people...
So... if you're online you can nudge other online people (without the offline contacts). If you're are as offline, you can nudge online people, but not recieve nudges...
And... If a contact nudges you, i suggest you block him or change your status to offline...
Or, if you don't like nudge's shake, you can apply the A-Patch.
But remember that this will stop the shaking for ALL nudges recieved...
Edit: Liked the ideas of Dazmatic and Quacky...
(Didn't create a new reply to say this)