>I Was reading about the MSDE Database Engine included in VS 6, that is recomended to use it instead the Jet Engine and VFP Engine as a preparation for the migration to SQL Server without additional programming when the app is going to be used with 5 or less users. What do you think?

I think that this is an excellent strategy. MSDE is fast, free, and robust. IMO, it's excellent for low volume LAN and Web Apps, and when your application outscales its 'tuned' limit, all you need to do is purchase a SQL license.