[nirajr]

email is a very generic communication, and in my opinion, it is possible to build tools on top of email that can give every collaboration/crm/project-management tool in the market a serious run for their money.

Every email front-end now supports extensions/plugins (for gmail, its gadgets+contextual api or DOM scraping), and of course there's imap to interact with the data, labels, headers and attachments. These two together yield a lot of potential to build a lot of tools that can be very useful.

We have built GrexIt (http://grexit.com) which allows Google Apps mail users to store email discussion from their inboxes to a shared area, where others who were not a part of the discussion can see them. This helps our users very easily create a knowledge base out of their work email. Some of our users are also now using GrexIt as a collaboration tool.