Steve Rubel has published a post about another pretty exciting product by 37signals called Highrise which is a content management/CRM tool which looks like it is going to blow my hair back when it launches.
The email feature alone is amazing. You forward an email from a team member to a specific address and Highrise will convert that email to additional content specific to that team member on the site. Wow! With a few rules you could basically automate a communications workflow really effectively. I am looking forward to trying this out and comparing its functionality to Basecamp.