Well, am a frequent user of Orkut! Orkut has evolved immensely and i guess everyone will agree with me..
It had frequent updates adding new features for better browsing experience.
I remember when orkut was first released, to reply to a scrap, we had to visit the senders profile, then open his scrapbook and then scrap him/her. Now its a lot faster with reply option in the scrapbook itself!!
One more thing of orkut that i have noticed, is how its fetches images while viewing the gallery section. Orkut first displays a low resolution images, rather a thumb of the actual image, and in mean time fetches the high resolution image.! Once the image has completely loaded, it just replaces the lower version(resolution) of the image!!
I have a simple html page to share! Click here to view
Orkut also prefetches other images in the gallery which could be simply done by having an array of images to be prefetched at page load.