Whether you’re packing an iPhone or a free-with-a-plan phone, the Opera Mini browser is a sweet little application. It’s a browser designed to minimize the volume of data that a mobile phone CPU needs to download to render a webpage, by compressing it on Opera servers somewhere in the cloud, and in some instances pre-rendering the page before sending it along to the phone.

There’s a huge potential market for Opera’s bandwidth-saving browser: Internet addicts who don’t have an unlimited data plan.

I tried the original Opera Mini a few years ago on my free Nokia phone. It worked amazingly well, except for pages that relied on Javascript. Today, Opera Mini supports Javascript and Ajax technologies that make Web 2.0 pages interactive without needing to reload the entire page for every change.

PC World writer Jared Newman has listed five reasons that iPhone users should try Opera. Reason Number One? Speed. Other reasons: Speed dial buttons for websites, in-page search that’s strangely missing from Apple’s Safari browser on the iPhone, and productivity enhancers including variable font size, full-screen mode, adjustable image quality — lower quality downloads a lot faster — and Opera Mini will save your website passwords, which Safari won’t.

Opera browsers have about 3 percent market share among the entire series, according to Net Applications. It’s likely that Opera users on mobile phones aren’t necessarily using the Opera desktop browser on their full-size computers.