It's so rare that I'm absolutely blown away by something in technology anymore. The last time I was overly impressed was when I learned Ruby on Rails for the first time. I think it's rare to be blown away, mostly because the industry is so iterative, so quickly - with each new application comes modest improvements over the last. That's particularly true in the user interface department, because-to put it bluntly-most developers are just abysmal at photoshop and being graphically artistic. Or perhaps they just lack the passion and desire to make something look sexy, rather than just being sexy under the covers.
Well I'm happy to say that that's set to change with 280Slides. Fire up your Safari browser and try it out - you'll probably forget you're even on the web.
I can safely say that I was unprepared for experiencing such a leap in UI design for web applications. I've never seen such attention to detail in a web app's UI - and the best part is, the interface is still so responsive, unlike most hefty JS apps (try, for example, using Google Presentations). I sincerely hope this sets a new standard for all of us web developers for usability in our web applications. Thanks 280 for pushing us forward.
Of course, while 280North was re-invigorating the web UI, they also managed to invent a new set of Javascript frameworks while they were at it - the NeXT/Apple inspired Objective-J[S] and Cappuccino. Of course, I'm still a little hung up on the UI to even start taking in the framework.
On a side note to all you developers out there, if I weren't doing my own thing, I'd be knocking down doors trying to get a job at 280North. I'm fairly certain they've set themselves up incredibly well for quick acquisition - they have a great shot at having Apple, Yahoo, and Google in a three-way bidding war for this little gem. So if you're in a big company or just not fully utilized, start banging down doors!