Categories to have Subcategories and filters...

It would be nice if all categories could be divided in to subcategories for each module a category tree so to speak just like the Ads module.

Then filter preferences for each module on a preferences page for the user given to filter each module as such...events, people, ads etc etc...

For Example with my Dancer Dates Site:

Say a user is interested in only International Latin Dancing of which there are subcategories like lectures, competitions, Celebraties, inspiration,  videos etc.

In a preference pain the user could select the categories they would like to see and only those would appear on the world map and only those would be listed as stipulated by the user in each module by default. they can choose to change it when on the screen via a drop down but the defaults would be set by the user....

Now if we want to make this even better, the users preferences could be watched and suggestions of material that they are interested could be displayed to the user (Artificial Intelligence so to speak) but I am sure this will take allot of work to add... 

The enhanced categories and filters would be a huge step in the right direction... especially for huge sites...

this would be great in my current project. I am working on a site for Panther enthusiasts (crown vic, mercury marauder, grand marquis, lincoln town car). I have a section called How-Tos. As an example, say I want to look up how to - change the oil. So, I go to the how to section and I see the categories listed by year. I click on the year, then I get a subcategory for which vehicle (crown vic, mercury marauder, grand marquis, lincoln town car). I click my vehicle and I get the answer I am looking for.

If anyone comes up with a way - please post fast. This would really make sites better, in my opinion.