Downloading binary files with cURL?

Heya Folks,

My question is quite basic, I have a page with username and password and when i hit a certain combination a file download thingy pops up - and in cURL when I
curl -d "user=XXX&pass=XXX" url

I see all the strange binary stuff (u know that unreadable thingy) - now I was wondering how to save that file binarically, any help would be greatly appreciated.

Another thing I am wondering about is cookies - i know there's a way to make them be used but how do I do it? what I want is to run one curl command that will log me in, say to these forums, and another one that will I dunno, post a message.. how can I do it?

Thanks people,
- Ben