The original alternative indy browser that gave Internet Explorer and Netscape a kicking, the latest version of Opera still has some fight left in it. While most other browser makers have long since purloined many of Opera's innovations (e.g. tabs, pop-up blocking etc), it's continued to evolve with as those cunning Norwegians continue to add some really nifty and unique features.
Perhaps the funkiest of all is Opera Link which syncs bookmarks and homepage selections between PCs that have Opera installed. Not only is this very useful because it gives you a uniform browsing experience across all your computers, it's also verily cool indeed.
Equally impressive is Opera's indexing capabilities. As you surf, the Opera has Norwegian elves slaving away inside your PC, indexing every word of every web page you visit. This means you can type words into the Opera address bar and it'll search every site you've visited to suggest related links. Anyone doing even the slightest amount of research will find this feature incredibly handy. Here's hoping Microsoft, Google and Mozilla purloin this feature soon too.
Opera may have been superseded by Firefox and Chrome but it has stealthily stolen a march on the others in the mobile and console space, with Opera now the browser of choice for most windows mobile and Symbian smartphone PDA and users. With Nintendo also offering Opera on the Wii, Opera's foot print is massive.