There are a number of cool little tools that the partners use to quickly populate user drop down lists.
Here are various blog posts and links to pick from in no particular order
which was updated here 3) http://dynamicscrmbyalfredo.blogspot.com/2006/09/recently-i-found-this-useful-blog.html
4) and back in the 3.0 Days http://blogs.infinite-x.net/2006/08/26/release-utility-to-generate-picklist-options-for-dynamics-crm-30/
Have you found an easier way? Feel free to share!