For years now cell phone providers have increasingly become more strict on their data plans. Almost all that claimed to have "unlimited data" have put caps on this or increased their prices to the point that it is completely unbearable. With all the restirctions, using a smart phone without a data plan is nearly impossible. I have, however, found a company that not only allows you to use a smartphone without a data plan, but there are no strings attached.
The company I am referring to is a small upcoming company known as Ting. Using Sprint's data coverage and a combination of Sprint and Verizon's voice, this company provides a service that only charges what you use at the end of each month. If you like, you can set an estimated usage plan, however, it is even similar than that. By setting everything to 0 usage a month you will simply be charged as you use data, texts, or calls. The prices are reasonable and there are no hidden fees at all.
One of my favorite things about this company is the customer service. They are very courteous and quick to reply. I have never once had a machine take my call during office hours or been put on hold. I have personally been contacted on their off days to solve my problems. It doesn't get much better than that.
Now for what you have been wanting to know. With Ting you have the option to disable any service from a device. Which means: Yes, you can disable or restrict data usage. This is the only company that I know of that does not require you to sign up for a data plan before purchasing a phone. If that is not enough, it gets better. There is no contract, you can cancel your phone service any time of any day with no charges.
The only thing bad about this plan is that they are still growing. They have restrictions on what phones they have available but their next goal is to make it so that you can transfer any phone to or from Ting without any extra charge. As it currently is, you buy a phone up front since there is no contract. This seems bad but it is quite the opposite. With a slightly larger up front fee, over two years (the average contract time) you will spend a significant amount of money less than any of their competitors.
I genuinely encourage you to at least give their site a look over, I believe anyone would be impressed. If you do decide to go with Ting, this link will provide you with $25 dollars off the purchase of any device: Ting.com. You will not be disappointed.