Has anyone had a problem with dust or sand getting between a skin and their Blackberry and it causing scratches? I am thinking about getting the black Seidio skin, but want to make sure it won't rub scratches in the device.

Well, unless it is heavy stiff dust, I would not worry about it getting inbetween the skin and the unit and causing scratches. It would take a lot of pressure and friction for it to leave a scratch.

As for sand...yes, I think if sand got inbetween the skin and the unit it would casue scratches, especially if friction and pressure is placed on it.