Change the look of orkut by installing these cool looking orkut skins.
But first You need to install:
1. Firefox Browser
2. Greasemonkey Plugin

You can see an awesome collection of cool looking orkut skins here, and all of those can be downloaded from here.

“Inside Orkut” has also featured some good orkut templates
namely pinkut, bluekut, creamkut etc. etc.

How is it done?
Greasemonkey is used to add some extra bit of coding to webpages, coding is done in javascript. So all these scripts are coded in such a way that on being properly installed they will execute themselves whenever you visit orkut.com page. I myself is very fond greasemonkey userscripts and event tried my hands on it a few days ago. You can read more about greasemonkey plugin for mozilla firefox here at en.wikipedia.org/wiki/Greasemonkey

Gtalk Emoticon is a firefox extension that lets you add emoticon while you are chatting in an in browser chat session of google talk. Almost all the MSN and Yahoo messenger emoticons are supported. It has been successfully tested on firefox 1.5 and 2.0,

-Download Gtalk Emoticons Firefox addon from https://addons.mozilla.org/firefox/4151/

- Or you may like to read more about this extension here

Orkut scrap book searcher is a firefox extension that adds a search box on your orkut page. With this search box you can search for any text, username or sentences in scrapbooks and in communities. User can also search for the data in the specified date range. Help box below the search box will help you in understanding all its features.

Install this Firefox Addon/Extension from here
Or you can use this search box through greasemonkey plugin, the user script for the greasemonkey plugin can be installed from here