Macworld UK reports that Opera has shown a preview of its iPhone browser at the Mobile World Congress in Barcelona. Opera co-founder Jon S. von Tetzchner briefly demonstrated the Opera Mobile for iPhone app, showing pages rendering very quickly due to page optimization on Opera’s own servers. Tetzchner indicates that Opera “compress[es] data up to 90 per cent” and is claiming that Opera should be “up to six times faster on 3G networks.” Other Opera Mobile for iPhone features include a tabbed browsing interface and support for saved passwords and bookmarks as well as the ability to automatically zoom in on text columns. Tetzchner notes that Opera has not yet been submitted to the App Store and speculation remains as to whether Opera Mobile will be accepted by Apple, although the new version of Opera has been written using native iPhone code rather than simply being a port of the original mobile app. Alternative browsers have been available on the App Store for almost a year, however Opera Mobile is unique in that it does not use the iPhone WebKit engine. Opera has not yet announced an expected release date for Opera Mobile for iPhone.