Opera has a very nice feature, which enable me to edit any webpage I’m browsing, without accessing the source files on the server. Of course, it’s only locally on my own PC – but that’s often just what I need. I just view the source (Ctrl F3), edit it, save it, and reload it from the cache (Tools -> Advanced -> Reload from cache)
When can this be useful? Well – when someone have a problem with some pages, I can just visit those pages and edit them locally, and see if it works. Much easier than download everything and set up a copy of the site locally to test, no? Or I may find a funny video clip I’d like to save on my harddisk, but the author of the pages have “forgot” to place a download link on the page to make it easy for me. No problem – I make that link myself. And then there are pages that just don’t work all that well – there may be some faulty scripts or whatever. Edit, save and reload – and the page shows itself from a better side.
It’s not the function I use most, but it has been very useful when needed. 😀