Forum Moderators: not2easy
<added>Put it profile temporarily.</added>
I just recently added three new custom buttons to my main toolbar: History, Cache, and Drives. The drives button lets me navigate my local drives faster than Explorer (Windows) and allows quick preview of new pages and then I can create a linked window to test all the page links.
You can find the indstructions to create your own custom toolbar buttons here: How can I customize the toolbar in Opera? [opera.com] Did I mention it is EXTREMELY EASY?
Also as you know by now, Opera has a built-in link the the W3C Validator which even allows you to perform validation checks on temporary preview pages that programs such as Homesite, DW, and other editors generate.
Finally, the ability to preview a new page and then disable CSS to see how your unstyled content displays is a tremendous asset. This is one of my personal favorites.