Adding an All Category

Does anyone know what kind of code and where I can add the code in order to get an “All” category for my posts?

I’d really like to be able to allow people to see all the posts at once.

Thanks.

[alternatively (or at the same time), is it possible to make a Page have all the Posts on it if – for instance – I don’t want to have all the posts show up on the home page?]