Use more than one category as a source

Is there a way to take articles from more than one category?

I don't want to have to put in the article IDs each time a new one is added

Article can belong to multiple categories, you can create one special category to associate articles with it.

Ahh, forgot that, I will give it a go

How do I do this exactly, thought I knew but being stupid

Well no , I have mistaken you can not assign article to multiple categories without additional components (I probably tough of virtue-mart products - sorry). Only way is to use ID list