Quick userscript to make HipChat more like irssi

HipChatOptimized.user.css

div.input {
  background-color: #555 !important;
  border-top: 1px solid #aaa !important;
}

.topic_container {
  background-color: #222 !important;
  color: #aaa !important;
}

.textwrapper {
  background-color: #000 !important;
  border: none;
}

#message_input {
  background: #000 !important;
  color: #aaa !important;
  padding: 3px !important;
}

.chat_display {
  background: #000 !important;
}

.atTag {
  background-color: #222 !important;
  color: #fff !important;
  border: 1px solid #333 !important;
}

.atTagMe {
  background: #222 !important;
  color: rgb(176, 167, 60) !important;
  border: 1px solid #333 !important;
}

.welcomeMessage, .systemMessage {
  background-color: #222 !important;
  color: #aaa !important;
  border-top: none !important;
}

.welcomeMessage .nameBlock, .systemMessage .nameBlock {
  background-color: #222 !important;
  border-top: none !important;
  border-right: none !important;
}

.welcomeMessage .messageBlock, .systemMessage .messageBlock {
  border-left: 1px solid #555 !important;
}

.welcomeMessage .nameBlock p, .systemMessage .nameBlock p {
  color: #aaa !important;
}
                                                      
.dateDivider {
  background: #333 repeat-x scroll 0px 100% !important;
  color: #aaa !important;
  border-top: 1px solid #555 !important;
}

.chatBlock.them, .chatBlock.me {
  background-color: black !important;
  color: #aaa !important;
  border-top: none !important;
}

.chatBlock.them .nameBlock, .chatBlock.me .nameBlock {
  background-color: #000 !important;
  border-top: none !important;
  border-right: none !important;
}

.chatBlock.them .messageBlock, .chatBlock.me .messageBlock {
  border-left: 1px solid #555 !important;
}

.chatBlock.them .nameBlock p {
  color: #aaa !important;
}

.chatBlock.me .nameBlock p {
  color: #eee !important;
}

chatBlock.me {
  background-color: #000 !important;
}

#roster {
  background-color: black !important;
  margin-top: 11px !important;
}

#roster .list .participant div {
  background-color: black !important;
  color: #EEE !important;
}

#chats {
  border-bottom: 10px solid #000 !important;
}

#message_input {
  height: 10px !important;
  outline: none !important;
  resize: none !important;
}

#chats {
  bottom: 20px !important;
  top: 11px !important;
}

.input {
  padding: 0px !important;
}

#upload_button {
  height: 10px !important;
  display: none;
}

input[name="Filedata"] {
  display: none;
}

#header {
  height: 20px !important;
}

.logo img {
  width: 64px;
  height: 29px;
  margin-top: -5px;
}

.topic_container {
  padding: 6px !important;
}

.top_bar {
  height: 18px !important;
}

.top_bar button {
  height: 18px !important;
  padding: 0px !important;
}

.tabs {
  height: 10px !important;
  padding: 0px !important;
}

#tabs {
  left: 105px !important;
}

#tabs {
  bottom: 10px !important;
}

#action_tabs {
  bottom: 8px !important;
}

HipChatOptimized.user.js

// ==UserScript==
// @name        HipChatOptimized
// @namespace   *.hipchat.com/chat
// @description Adds "Toggle sidebar", removes "Send" and adds a dark, irssi inspired theme.
// @include     *
// @author      Joakim K
// ==/UserScript==

(function () {
    var showSidebar = false;
    var themeCssUrl = "https://gist.github.com/raw/935608/6e644b3058f12534e4a921d698b6d1828b2360ab/HipChatOptimized.user.css";
    var themeCssUrl = null; 
    var previousWidth = 0;
    var uiLoaded = false;
    
    function updateWindow()
    {
        if($("#main_chat")[0].style.width != "100%" && !showSidebar) {
          previousWidth = $("#main_chat")[0].style.width;
          $("#main_chat")[0].style.width = "100%";
        }
        
        if(showSidebar) {
            if($("#main_chat")[0].style.width == "100%")
                $("#main_chat")[0].style.width = previousWidth;
            $("#sidebar").show();
        }
        else
            $("#sidebar").hide();

      if(!uiLoaded && $("#tabs a.open")[0]) {
        uiLoaded = true;

        // Update window when the channel is changed
        $("#tabs a.open").click(updateWindow);
      }
    }

    if (window.fluid) {
        setInterval(updateWindow, 500);
        
        $("#send_message_button").hide();
        $("#top_bar .topic_container").after('<button class="silver" id="toggle_sidebar" style="height: 24px; position: absolute; right: 191px; top: 5px; width: 110px;">Toggle sidebar</button>');

        if(themeCssUrl)
          $("head > link[rel=stylesheet]").after('<link rel="stylesheet" type="text/css" href="' + themeCssUrl + '">');

        $("#toggle_sidebar").click(function() {
            showSidebar = !showSidebar;
        });
    }
})();

Made the menus and input more compact so that more of the conversation text is visible with a small window.

Screenshot: http://dl.dropbox.com/u/136929/hipchat-theme.png