Svein,
It is possible to create an InfoPath form that can be accessed from a web
site. Usually this is best done via a SharePoint form library. You will
however need to ensure that each user accessing the form has InfoPath
installed on their local machine before accessing the template. As for
submitting back to a database. InfoPath provides the ability to drectly
connect to SQL, Access, XML and Webservices. If you have mutiple users who
may be using the form at the same time I would recommend they submit their
data to either a SQL database or a web service. This would circumvent any
potential concurrency issues.

Hope this helps

Cheers
Ben Walters

Svein,

If you use a Sharepoint/WSS document library, and use the Form Options to
specify columns to add to the form library upon post, you can then report
directly from the WSS data.

Using a Web Service may be required, though, if you can't expose sharepoint
to the internet.