Today I've passed the 70-631 exam: Configuring Microsoft Windows SharePoint Services 3.0. Together with my colleagues: Erik Schoenmakers and John Bruin I have scored 1000 points. By passing this exam I have completed the SharePoint 3.0/MOSS 2007 certification as defined by Microsoft.
I've found the 70-631 exam the most abstract to learn. I'm a developer not an admin. Looking at the questions though, there are quite many questions about various server configuration-related stuff.
Does passing all the four exams mean that I'm done with SharePoint? Absolutely not. While it's not really the beginning of the road, it's definitely not the end. Stay in touch for more SharePoint information.