This topic is pretty old, but this is exactly what I had in mind for my site. I would like to create multiple categories and I know that everyone isn't interested in all of them (namely the sports that I like to write about).
I was thinking of having a list of my categories on the right sidebar with a checkbox next to them. By default they would be all checked, but a user can uncheck them as s/he pleases. A cookie would be stored on the local computer so that these category selections would be saved for the next visit. A checkbox form like this should suffice:
Music [ x ]
Web [ ]
Sports [ x ]
Games [ ]
If "music" and "sports" were selected, once the user hits "submit" on the form it would take them to http://www.website.com/index.php?cat=1+3. (assuming they were categories 1 and 3 respectively)
Unfortunately, while this form doesn't seem like it would be too difficult to make, I'm not especially savvy in these kinds of things. I know even less about incorporating cookies. Can anyone please help or lead me in a better direction? Thanks in advance.
(Also, unless I'm misunderstanding the post above that suggests solving this within the database, wouldn't that require users to register before their settings can be saved? I don't have visitors register, so this would not work for me.)