It's also a content aggregator and you can add files, pull in content via RSS, integrate office content (Zoho Writer, spreadsheets, presentations, calendars, etc) and even full-fledged applications can be aggregated into Notebook - for example from Zoho Creator. In some ways the aggregation parts resemble a personalized start page.

The best part of Zoho Notebook though is its collaboration features. You can share a whole Notebook, or just pages - and even just parts of pages, which Raju calls "sharing at the content level". It enables collaborative editing, so that more than one person can edit a notebook at a time. It also has version control too and access controls. A neat value add is that you can show the Skype status of the users.

Raju has a video up on YouTube that explains more about the product.

I asked Raju about possible use cases. He told me that a student could use it for compiling research, or enterprises could use it as a project management tool - to gather project documents into one notebook and collaborative on them from within Notebook.

The product is pre-beta and won't be released until March, but it is being announced at DEMO. Right now it still has some issues to be ironed out - e.g. I had trouble inserting some bits of content. But you can see the promise of an online and collaborative Notebook application, especially one that handles multiple types of content. Game on Google, not to mention Microsoft!