I think Highrise is a very useful application. The way it allows you to track the history of your contacts is very helpful when working through a negotiation or starting out with a new client. I am also very happy with both Backpack and Ta-da Lists. I especially like the interface designed for Ta-da Lists on the iPhone. I have used both Basecamp and Campfire as well, but did not see an immediate use for them. My software development is done using Trac, so Basecamp seemed a little redudant.

Your products are pretty useful for project management. I am running my own small business. I find Campfire is a good tool for team communication and sharing network. Doris