What’s The Best Opensource Or Web 2.0 Tool For Manageing Customers And Projects (crm’s)?

There are 2 sites that I love.
Basecamphq.com is one of my favorite. You can create full featured projects, reports and manage all of it. The one thing BasecampHQ is sorely missing is Invoicing features. While Basecamp isn’t for HUGE enterprise situations, it is perfect for consultants, or medium sized companies that need to manage projects online. Basecamp makes extensive use of AJAX, so I believe that qualifies it as “Web 2.0″ (even if I think this term has become FAR to loose)
Basecamp even has a great 3rd party commercial Firefox extension – Basecode. This really extends Basecamp’s features, and makes mundane things like formatting 10x better.
Alternatively, there is sitejobtrack.com; this site uses AJAX as well. It primarily focuses on invoicing, reporting and project management. The client integration and consultant integration features are much less than Basecamp, but the invoicing cannot be beat.
In all, my vote is for BasecampHQ. I use it extensivley, and use QuickBooks Online for invoicing.

I really like http://www.opensourcecms.com because you can compare and better yet demo each of the CMS that are available as open source. It really helps to find out which ones work well before downloading and installing them yourself.