If I take the sim card from my iPhone?

And put it inside an unlocked blackberry I got from eBay, will I still have Internet? I want to get rid of Internet on my phone. No Wi-Fi either.

Yes you will the sim card is what connects your phone to everything you could call your provider (verizon at&t sprint ect.) and ask them to disconect the internet

1st off, iPhone to BlackBerry, bad idea.

2ndly, yes. Switching SIMs does not change how the phone works or what kind of phone it is. I say that because both are smartphones & data plans are mandatory for them.