A few quick'n'dirty IRCCloud-related bookmarklets.

IRCCloud Hide people.js

var p = prompt( "People to hide, comma-separated" ),
  sel = [],
  chng = { 
    opacity: 0.3,
    fontSize: "90%"
  };

if ( p ) {
  p = $.trim( p ).split( /\s*,\s*/ );
  sel = $.map( p, function( name ) {
    return ".author:contains('" + name + "')";
  }).join( ", " );

  $( "div.scroll" )
    .find( sel )
    .closest( "tr" )
    .css( chng );

  $( "div.scroll" ).bind( "DOMNodeInserted", function( evt ) {
    $( evt.srcElement )
      .find( sel )
      .closest( "tr" )
      .css( chng );
  });
}


// Bookmarklet version

javascript:var p=prompt("People to hide, comma-separated"),sel=[],chng={opacity:0.3,fontSize:"90%"};if(p){p=$.trim(p).split(/\s*,\s*/);sel=$.map(p,function(a){return".author:contains('"+a+"')"}).join(", ");$("div.scroll").find(sel).closest("tr").css(chng);$("div.scroll").bind("DOMNodeInserted",function(a){$(a.srcElement).find(sel).closest("tr").css(chng)})}

IRCCloud Highlight people.js

var p = prompt( "People to highlight, comma-separated" ),
  sel = [],
  chng = { 
    backgroundColor: "#efe"
  };

if ( p ) {
  p = $.trim( p ).split( /\s*,\s*/ );
  sel = $.map( p, function( name ) {
    return ".author:contains('" + name + "')";
  }).join( ", " );

  $( "div.scroll" )
    .find( sel )
    .closest( "tr" )
    .css( chng );

  $( "div.scroll" ).bind( "DOMNodeInserted", function( evt ) {
    $( evt.srcElement )
      .find( sel )
      .closest( "tr" )
      .css( chng );
  });
}


// Bookmarklet version

javascript:var p=prompt("People to highlight, comma-separated"),sel=[],chng={backgroundColor:"#efe"};if(p){p=$.trim(p).split(/\s*,\s*/);sel=$.map(p,function(a){return".author:contains('"+a+"')"}).join(", ");$("div.scroll").find(sel).closest("tr").css(chng);$("div.scroll").bind("DOMNodeInserted",function(a){$(a.srcElement).find(sel).closest("tr").css(chng)})}