That's right. I often have mixed emotions on this one. Let's say we have some type of site that profiles different items. For example, the latest thing over the past few years is tagging... and it's cool. I'm trying to make up my mind on what is better: categories, tagging, or both (in terms of setting up a site with such functionality). If I do tagging, I'm thinking about limiting it to something.
What are your thoughts? Are both needed?
One problem is if I do only tagging, I don't want to do a tag cloud... because then some items that have smaller tags would be smaller and probably not get as much attention (assuming the tag cloud shows tags font sized based on how much it's used).
And then, if I do only tags, do I make it user-defined, or do I define it myself for people to choose? For as much as I'd like to say user-defined, I'm not sure how I'd display all of the tags.
I'm kind of leaning towards tagging, limit to 5, and pre-defining the options (similar to what this site does). Being able to easily find the items if someone was clicking through the site is also noteworthy.