From their e-mail:
"Free Ground Shipping on orders over $100 now through Sept. 21 Use promocode SEPTSHIP at checkout*
* Get free ground shipping on orders over $100.00. This offer applies to orders placed online through Patagonia.com or via phone, fax or mail through Patagonia Mail Order (does not apply to shipping from Patagonia Retail stores). Offer applies to ground shipping in the United States only. Not valid for expedited shipping or addresses outside of the United States. Not valid with any other promotional, team, group or special offers. Free Ground Shipping offer ends September 21, 2009."
