Done, Godfrey:

// Based on a script in Mark Pilgram's upcoming "Dive into Greasemonkey", as well as "renamer"

// ==UserScript==
// @name Eliminate excessive exclamation points
// @namespace http://www.zieak.com
// @description Turns 2-42 exclamation points into just one
// @include *
// ==/UserScript==

// Why 42? We should ask Earth before it is too late.


(function() {
var replacements, regex, key, textnodes, node, s;

replacements = {
"!{2,}": "!",
"\\?{2,}": "?",
"\\.{4,}": "...",
};

regex = {};
for (key in replacements) {
regex[key] = new RegExp(key, 'g');
}

textnodes = document.evaluate( "//body//text()", document, null, XPath...

Done, Godfrey:

// Based on a script in Mark Pilgram's upcoming "Dive into Greasemonkey", as well as "renamer"

// ==UserScript==
// @name Eliminate excessive exclamation points
// @namespace http://www.zieak.com
// @description Turns 2-42 exclamation points into just one
// @include *
// ==/UserScript==

// Why 42? We should ask Earth before it is too late.


(function() {
var replacements, regex, key, textnodes, node, s;

replacements = {
"!{2,}": "!",
"\\?{2,}": "?",
"\\.{4,}": "...",
};

regex = {};
for (key in replacements) {
regex[key] = new RegExp(key, 'g');
}

textnodes = document.evaluate( "//body//text()", document, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

for (var i = 0; i < textnodes.snapshotLength; i++) {
node = textnodes.snapshotItem(i);
s = node.data;
for (key in replacements) {
s = s.replace(regex[key], replacements[key]);
}
node.data = s;
}

})();