Controllers inside sub folders

[eluser]DLhendup[/eluser]
I am developing a site that has many modules. for eg. yellowpages, news, blogs etc. and they would be organized in the following way:
www.site.com/yellowpages
www.site.com/news
www.site.com/blogs

Can anyone please tell me if it's okay to arrange controllers in folders, like as follows:

controllers/yellowpages/category/add

In the above, "category" is a controller and not a method. "add" is the method and Yellowpages is a subfolder under controllers, and is a module.

controllers/news/view
controllers/news/add
Likewise, news is just a folder and not a controller.

So, will the above folder arrangement work, or do I have to store all my controllers in the controller folder itself? What if I have a controller by the name of "yellowpages" inside the controller main folder? Will it clash with the subfolder by the same name?