As you probably know, for some time the facebook fan pages can like one each other, just as they are personal profile. With the difference that when a page likes another, that is said on the lower left part of it. It's pretty much like linking to another fan page from obvious place. So why not like/link exchange? There should be already places for arranging deals like that, do you know any?
Why don't you just like their page and post your page advertisement? It is more visible to their fans. Of cause, you can get banned on some pages, but they are usually others organisation pages.
page to page spam? I'm not sure that's the way i want to go. Althought it might be worth it if targeted properlyÂ
Well, just be honest and target the right place, you should be ok. Don't you know if you give a Facebook page link, people will click on it more than an outside link?