Orkut Theme Generator lets you create your own orkut themes. While it is good to have a different theme for your orkut profile, these themes are nothing but waste of time because the themes you create are only visible to you.

If you still interested to see a different theme in your orkut profile, go here and enter an image URl to use as a background image for your new theme and give a name to your theme and click create theme. Voila you now have the most beautiful orkut theme in the world. Once you hit the button it will generate a userscript for the same, you can add this userscript to your browser to get the new theme. You need Greasemonkey addon for userscripts to work in Firefox.