Drop.io has turned the web browser into a live, interactive, rich media space. Their new interface allows you to upload files, leave comments, and chat, all in real-time. This is the coolest way to interact with the cloud that I've seen so far.
This is a step above Google Docs because of the beautiful, easy-to-use interface. The web app runs much smoother than Docs and there are far more tools for collaboration. Drop.io is also much smarter; it knows what type of file you are uploading and it separates them on the page much cleaner than Google.
It not only works with the drop.io web interface, but you can use the Firefox drag & dropio plugin or even email to share files. Going forward they have full support for third party chat services like Adium. Also full mobile support for iPhone, Google Android and other carriers.
I can see this being used a lot with live events, team collaborations, and any instance where you want to send a file to a friend for quick download. Now Drop.io isn't just about sharing files, but collaboration. Real-time interaction with someone on the other side of the screen.
Google and Yahoo are slipping behind, and the smaller, more innovative companies like Drop.io are taking over in this space.