Attaching info

[Ploo]

So here's the case. Each one of my products needs to have 3 fields attached to them with some info which needs to be filled in. This will apply to nearly every product and since there will be a lot of them I don't want to have to keep on adding these 3 fields to every product.

So I figured I could have an item which is free which will have this info attached but what if a customer doesn't add that item? How would I make it auto-add and make it un-removable?

Another solution I thought of is just asking the user for the 3 piece of information just as he's checking out but I didn't find any way of doing that.

I want to use ready made modules/functions, what could I do?

Thanks.