Having more posts visible on category pages and the blog page

I have created a few category pages. On each category page, the last blog post of that category is visible but you have to either hit the page numbers at the bottom (if I have that enabled) or hit earlier posts. Is it possible to have several posts visible on the category pages? Or even on the blog page?

I know that you can set the number of posts visible on the presentation (home) page – is this possible on the blog and category pages.

Thanks,

Kat