Can I just transfer my number?

I've wanted an iPhone since before I even had my iPod Touch, but I don't want to pay for a data plan. I'm not going to use it-I'll use wifi whenever I need internet if I can connect. I know Verizon Wireless wont sell one to you without upgrading your plan, but what if I get it somewhere besides the Verizon store?

So, my question is: If buy an iPhone from Amazon or where ever, can I simply transfer my number from my current cellphone (Samsung Bright-side on Verizon) over to an iPhone without a data plan? Will that work? Will it not work until I do get a plan or something?