Besides the powerful Safari browser that comes with the iPhone, Opera Mini is perhaps the best and most capable mobile browser out there. New in version 4.1 (beta) are speed improvements that Opera claims are up to 50% compared to 4.0, the capability of saving pages for offline viewing in certain phones, and file downloading without recurring to the phone's native browser.
Opera Mini tries to cater to a wide range of phones using the Java ME platform, thus requiring that to function. Nevertheless, it's a free.
To download Opera Mini 4.1 beta, visit mini.opera.com/beta using your phone's existing Web browser and click on one of the links to download Opera Mini. Alternatively, you may download Opera Mini to your computer for a manual installation.