This might be a bit late because I forgot to write an entry about it earlier, but they are giving away free registration codes in conjunction with the Opera 10-year online anniversary party. The registration codes will make your copy of the Opera browser ad-free! Normally, you have to pay 39 USD to make it ad-free. Get the codes now before it’s too late and download a copy of the browser! This offer is only valid until 12 a.m. Wednesday, August 31 2005 (PDT). I think you should get it. You might not want to use Opera as your main web browser but you can always use it to test whether your website designs are compatible or not with Opera. That’s a good enough reason to take up on the offer.
Update: The free offer is over now, though you can still get the registration codes by participating in their affiliate program, which basically means putting their banner on your site and try to get 250 people to click on it before you can get yourself the registration codes. It was so much easier when it was free. ;)