I just saw a demo from Steelray (knowledgepm.com) that is browser-based access to an MS Access or MS SQL Server database created from MS Project. I think you have to start with MS Project, then save it as an .mdp or SQL db, then upload to the web site, then anyone with a browser I think can update it from there, or the person with MS Project can overwrite it. About $100 per user, which can be concurrent if they read only or per named user if you need to update etc. If you check this out please update me with your feedback.