I'd like users to be able to write pages, group them and give to each group a title and some keywords. Then if a group was made "public" other users (including anonymous users) should be able to search trough "titles".

This just looks like letting people add taxonomy terms/tags and assign them to pages with some extra bits.

Since I'm not planning to let people build a categorization tree I could hand code all this. Right now I can't see the advantages of bending taxonomy especially because I may add some extra information to the "group" (eg. score of a group, private bit and other extra fields that will be used to filter groups by different criteria other than "title"), and I could use DB facilities for full text search. But maybe there is a module ready that mostly fit or fit my needs.

I'm mainly looking for on field experience on "user tagged content" and search.

Group of pages may be something like: - food I like most - books I should read - books to prepare XXX exam - food I should learn to cook - spicy food

and other users should be able to perform full text searches through titles.

Letting users share the pool of already inserted tags is going to be very slow, limit the expressivity of the "title" and still since each user may decide if a group of articles is public or private I won't be able to actually share groups.

On the other side maybe sharing tags may promote the choice of popular tags and avoid scattered categorization.

Maybe I could just offer both... private group titles and shared tagging.

thanks