It's interesting that so far everybody seems to ignore the last part of the question, which seems to me interesting enough: is unit testing useful for web apps?

It's interesting that so far everybody seems to ignore the last part of the question, which seems to me interesting enough: is unit testing useful for web apps? In my experience, I can tell that I'd really like to be able to use them, but changing my apps to fit them would make them a lot "thicker". Let me explain. When I make a page in a web apps which does something, the code is very thing. It has roughly 3 layers: sql database (static, no stored procedures), business logic including sql statements (java), and html template (in my case html+apache velocity). There is no POO dividing my apps horizontally. In order to make this testable I'd have to basically put another layer on top of everything. I still have no idea how to do it without making everything horrible.