I'm very excited about the launch of Gist here in Seattle.  I have known CEO TA McCann for many years dating back to some time spent working together at MessageGate.  I have also been providing some advice and feedback as the company has gotten closer to formally launching so I am biased in my enthusiasm for what they are doing.  The company has gotten some great initial local buzz:

Xconomy Seattle:  Getting the Gist of Gist, from Entrepreneur T.A. McCann
Northwest Innovation:  Interview with T.A. McCann, Gist
John Cook Venture Blog (formerly of the Seattle PI)

I have seen the side of trying to track, monitor, and control email during time spent at MessageGate and Orchestria from a security and compliance perspective and at the core of it all were people just trying to do their jobs.  Gist is about the individual and helping them combine email and web-based content to be better at doing their jobs.  It does this by combining the best of messaging, search, and personal feeds to help build relationships.  There are lots of companies focusing on rethinking the inbox like Xobni and I have stated previously that this is valuable but doesn't address the entire problem.

I encourage you to register for the private beta and take it for a spin.  I know they are working to process all the requests they have received as well as to improve the product based on the feedback they are getting.  I'll post some additional thoughts as I use it more on a daily basis.

An early example of how I used it was when a friend's company acquired a company and I was alerted to it not by a keyword alert email or actually receiving the press release but by that bit of news being brought to my attention because we trade emails (that's how I knew Jim).  Pretty cool, huh?