Different numbers of posts front and else

Hi,

I need to display a smaller number of posts on the front page, and a larger number elsewhere. To be more precise, I want 3 posts displayed front and 15 posts on category or archive pages.

If I set the post number option to only 3, the 3 are used for all pages. If I set it to 15, the front page gets also 15.

I saw this plugin alright:

http://wordpress.org/support/topic/11211?replies=20

but I can’t piece it together so that it does properly what I need it to do.

Is there maybe an easier way to do this? Or is there some other plugin with which to achieve this? Search turned up only the above link for me.