With the advent of the Opera 10 Beta, I highly recommend that users check it out or upgrade to it. The biggest news is that one of my primary gripes, i.e., the lack of inline spell-checking, has been solved.
Opera 10 Beta 1 can be downloaded here. For some reason though, the interface does not allow you to choose the QT4 builds. These are available by browsing through Opera's FTP server. There is also only an RPM available for the QT4 build, which means that you'll need to install rpm on your Kubuntu system to install it.