After you install the Web Services Enhancements 2.0 Technical Preview, VS.NET 2003 should have a menu item for “WSE Settings 2.0” when you right click a project:

WSE Settings 2.0 Project Menu Item

If it doesn't, then try renaming the following registry key:

HKCU\\Software\\Microsoft\\VisualStudio\\7.1\\PreloadAddinState\\

Courtesy of Scott Bloom in the microsoft.public.dotnet.framework.webservices.enhancements newsgroup.