I created a greasemonkey script for Firefox that does that somewhere earlier in the thread. Also working on what you mentioned just know H2odysee said the json was changing.
JR
Been using that since you posted it thanks, also works in chrome (install the the tampermonkey extension)
Code to save people searching
// ==UserScript==
// @name Middlecoin
// @namespace middlecoin
// @include http://middlecoin.com/
// @include http://www.middlecoin.com/
// @version 1
// @grant none
// ==/UserScript==
var username = 'put.your.bitcoin.address.here';
// get all rows excluding the first one and the one with your username
var rows = document.evaluate('//table/tbody/tr[position()>1 and not(contains(., "' + username + '"))]', document, null, 6, null), i;
for (i = 1; i < rows.snapshotLength; i += 1) {
// hide all of them
rows.snapshotItem(i).style.display = 'none';
}