The next version of Opera will support extensions. Would be great if you could make one!
Matt Cox commented
The correct and latest Opera extension from Diigo is here:
D T commented
As far as I can see one is already available: https://addons.opera.com/en-gb/extensions/details/diigolet/?display=en
Paul Bohrer commented
Indeed, it would be very good. In Opera 11 bookmarklet works, but isn't stable :(
Sha Ndi commented
Yes please, beside the current bookmarklet don't work with the opera next version anyway.