Firefox only!
I just finished writing my own Poke All script for Greasemonkey. Using it ispretty straight-forward, I basically added a single button you can use to poke everyone that has poked you. After everyone has been poke, a “close” link appears next to the Pokes header. Clicking this link will close the entire section — with a nice animation too!
You can get the script here. Or if you don’t have Greasemonkey for Firefox, you can install the Poke all Firefox extension I compiled using this compiler — just save it to disk and drag-and-drop it into Firefox, and choose to install.

