Dropbox sweats the user experience details as commendably as it masters the considerable engineering challenges required to reliably sync files everywhere a user may need them.

With consumers buying two smartphones for every desktop computer they purchase, the demands, challenges and opportunities of the mobile space are reshaping our assumptions about design and user behaviour.

I like files. I like editing a CSS file without necessarily having to edit an HTML file. I like fixing a problem by replacing a corrupted file with a clean one. Maybe I'm set in my ways, but I don't consider it a hardship to open a folder or replace a file.

I could open a thousand Excel documents and still never think to scroll past a wall of empty rows to see if, hidden beneath them, there is a tab I need to click. Just doesn't occur to me. Because, design.

Even if it's not always the best markup, what are Facebook and Twitter? They're web standards with some scripts. They may not validate, but they're still CSS layouts and simple markup, and that's great!

Wildly successful sites such as Flickr, Twitter and Facebook offer genuinely portable social experiences, on and off the desktop. You don't even have to go to Facebook or Twitter to experience Facebook and Twitter content or to share third-party web content with your Twitter and Facebook friends.