mack - 9:05 pm on Apr 17, 2010 (gmt 0)
Opera mini uses server side compression, thats why its quicker than most conventional mobile browsers. When you request a page, your request is sent to Opera's servers. The servers then make the http request for the content, compress it and return the compressed format to your browser.
You can more or less visualize the process by looking at the status bar.. Very slow to begin with then it speeds up.