Option of shipping or sent via email?

I want to add a product that can either be:
Sent to the buyer online (no shipping costs)
or
Give them the option to have the item posted/shipped to them. (will have shipping costs.

Want to price the product differently for each option also.
Can anyone tell me how to do this under one product listing, or am I going to need to put up the same product x2 to offer seperate options on ship or no ship?

Thanks

Should be able to set the different options easily in the attributes controller. Make online one option and ship the other.

Yes, but then how do you set one option to charge postage and one not to?
Thanks

Unless you have a tare problem, setting the weight to zero should suffice.