I wanted to upgrade our XSOLive.com demo site to Sharepoint 2010 for months but never found time to mess with it. Then something got messed up on the server and fixing it was more work than upgrading. A lot more work, as it turned out. Moving the database was much less effort than I expected.
On the old server, I logged in using SQL Management Studio, detached the sharepoint database and copied it to the new server and attached it to the new site, mounted it and upgraded it to the new sps design using this code:
For the complete steps, see this technet article:
Attach databases and upgrade to SharePoint Server 2010
