EtherPad is not likely to win a price for its user interface design, but it might just be one of the most useful web apps we have seen in quite a while. EtherPad allows you to instantly create a workspace for text documents that you can then share with your colleagues, clients, or friends. Every edit to the document will immediately appear on your co-workers' screens in real-time.
EtherPad acknowledges that Google Docs already allows for a similar kind of collaboration, but compared to EtherPad, Google Docs is clunky and slow when you just want to collaborate on a simple text document.
EtherPad would be a great tool if you want to keep collaborative notes during a conference call or meeting, but you could also use it to draft or edit text for a press release or email collaboratively.
EtherPad, for example, doesn't require you to sign-up before you can start working on your document. You can also just share your workspace's URL with your co-workers and they, too, don't have to sign up. Indeed, you can't even sign up for the service, which may become a bit of a problem if you want to go back to a document you worked on earlier, but don't remember the randomly assigned URL.
Google Docs requires you to send email invitation to all your collaborators and updates to documents don't appear in real-time.
EtherPad also has a versioning system that allows you, or anybody else with access to your workspace, to save the document at any time.
As is often the case, the most useful tools are those that have a relatively restricted feature set, but allow users the freedom to use them as they see fit. EtherPad is one of these services and it will probably become a standard tools for us very soon.