Take photos of your home or, even better, make a video showing the contents. Describe the items, their acquisition dates and their costs or approximate values. Then store it in a safe-deposit box. This is the best proof you can have if the property is ever damaged by a natural disaster.
Casualty loss deductions for 2010 are limited to the damage sustained, minus insurance reimbursements, in excess of 10% of your AGI (after subtracting $100 per event).