When we Say SharePoint, we refer to two product of Microsoft (WSS and MOSS). On certifications front also, Microsoft has released 2 certifications each on SharePoint and WSS. One of the certification deals with the application development and others deal with the administration.
Below are the certification details
MOSS certification1. SharePoint Server 2007 ― Application Development certification
http://www.microsoft.com/learning/en/us/exams/70-542.mspx2. Microsoft Office SharePoint Server 2007 – Configuration credential
http://www.microsoft.com/learning/en/us/exams/70-630.mspxWSS certification1. Microsoft Windows SharePoint Services 3.0 – Application Development certification
http://www.microsoft.com/learning/en/us/exams/70-541.mspx2. MCTS: Windows SharePoint Services 3.0 – Configuration certification
http://www.microsoft.com/learning/en/us/exams/70-631.mspx