Nice, I'll try that. Here's my bookmarklet for highlighting recent comments (subtly for <1h old, less subtly for <10m old):

  javascript:var jq=document.createElement("script");jq.src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js";document.getElementsByTagName("head")[0].appendChild(jq);window.setTimeout(function(){jQuery.noConflict();jQuery("span.comhead:contains('minutes ago')").parent().parent().css("background","#fdfdf0");jQuery("span.comhead:contains(' 0 minutes ago'), span.comhead:contains(' 1 minutes ago'), span.comhead:contains(' 2 minutes ago'), span.comhead:contains(' 3 minutes ago'), span.comhead:contains(' 4 minutes ago'), span.comhead:contains(' 5 minutes ago'), span.comhead:contains( '6 minutes ago'), span.comhead:contains(' 7 minutes ago'), span.comhead:contains(' 8 minutes ago'), span.comhead:contains(' 9 minutes ago'), span.comhead:contains(' 10 minutes ago') ").parent().parent().css("background","#ffffe9")},500)