Does anyone know the best/cheapest place to rent a pick up for the day in Fairfax County? Ideally something close to Fairfax.

I'd almost bet that UHAUL would be your best bet. Lowes and Home Depot only rent out IF u buy something from their store and need to haul it home.

I do not know about a pick up truck, but I have rented cargo and passenger van from Kip Killmanss Tysons ford in vienna and have had exceelent service from them.

Just get the insurance. That way if you bang up the vehicle it is there problem not yours.

I found Enterprise's rates are cheaper for utility vans and trucks than U-haul.