you could just remember it yourself! creating the ultimate live web 2.0, where once a user enters a username and password, you actually have to verify it at that exact moment or else they can't login! then you could hire midgets and have them remember and rebuild profiles for people and unicorns and...

anyways, i thought most (simple) desktop apps store data in text files? (perhaps encrypted?) it's definitely possible to store data in text files for web apps but seems inefficient for many reasons - speed and scalability being the first that come to mind. i've stored data in text files before for very simple apps that contained a couple of fields and had no sensitive information.

my personal suggestion: go with MySQL. it's free, well documented, efficient, scalable, etc. the list goes on...

That is his obtuse way of saying you don't have to use an RDBMS. You will still use some sort of database of course (Filesystem, BDB ... etc).

The same way desktop apps do: write it to disk.