Auto SEO URLs

I've seen some extensions for doing this, but it would be nice if it can be generated automatically.

For example, if the product's title is Samsung SyncMaster 941BW and it's product_id=33, and it's under category Desktops with category_id=20, then the auto SEO URL would look something like this:
This way, there would be no duplicated items/categories and every URL would be unique.

Products can belong to multiple categories

Adding the id makes the URL ugly and is really not needed

Therefore the only real way of doing it would be

I agree with do put a category path to a product link as it can belong any category.
However, the product id should be an option to add in a product link, because there are same name product only id/mode number is different.
So, I prefer http://domain.com/samsung-syncmaster-941bw.html as a product link.