Do iphone 3g or 3gs headphones work with a blackberry?

I have iphone 3g headphones and well basically they work fine when plugged into my laptop but they just don't seem to work when i plug it into my phone

The earphones you get with the iPhone should work in most headphone inputs. I think some models of blackberry though have a different size of socket. It may depend on the kind of blackberry.
most headphone plugs for mobile devices are micro jacks, these are basically universal so I don't see it being different from that.