I thought I was missing something in SQL Management Studio, as I couldn't believe the functionality to export or script database diagrams wasn't included. I went off to Google to search for something, either how to script it myself, or some missing function.
First I came across this post, but wasn't to inclined to copy/paste the script and clean it up. I later came to find out it was for SQL 2000, and would not work in 2005 (good, saved some time there). I continued my search and found an article on Code Project that provided SQL scripts to do exactly what I needed. The scripts are actually 2005 updates of the 2000 scripts I found on my first search.
Even if my Google search fails, I need to remember to hit up Code Project, it's a wealth of information.
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.