Love the Cloud, sold by Basecamp

So I just signed up for Basecamp project management and it's all going, I've got three projects loaded, two companies staff with access and it all works!

As a business user why would I try to do anything in-house any more. If there's a cloud or Saas offering then lead me to it. We are currently looking at installing Exchange, but now I seriously wonder if we wouldn't be better with Google Apps? We will almost certainly go with SalesForce.com to replace our decrepit Goldmine CRM (don't get me started on Goldmine - now there's a company that deserves to lose all its customers and go broke).