Just an FYI --
The US Mint website says there will be free standard shipping on domestic web orders starting today (Friday, July 26th). I called the Mint this morning and the operator said that this will continue through September 30th.
I had called to cancel my order that I placed on Wednesday the 24th. She said it's shipping today and it's too late to cancel. She said they also can't retroactively waive the shipping fee because my credit card has already been charged.
