How to hide product price

How to hide product price ? i going to price my product 0 that's why i want to hide it because i am going put options for the size of my product instead of categorizing it

example
Cat 1
--- Cat 1.1 - Pro 1.1.1
---- Cat 1.2
-----Cat 1.3

what i want is

Cat 1
-- Prod 1.1.1 -- option size

Hide product price where? Product page? Category page?

You just need to edit the associated template files. I.e. Product page edit /catalog/view/theme/[themename]/templates/product/product.tpl search for $special, it's around that line