This is the last 20% coupon I got. it was from last year. Fall sale? see the 6th exclusion. I cut and pasted from my email:

20% Off One Item
*Offer Exclusions:
Offer valid 09/07/07 - 09/16/07.
Coupon (or coupon code) must be presented at time of purchase. Online and phone customers must use code FALLCPN7 to receive this discount.
Offer not valid on REI Adventures or REI Outdoor School.
REI membership is required at checkout. Not a member? During checkout, you can join for a one-time fee of just $15.
Offer not valid on special orders, package discounts, prior purchases, REI gift cards or E-gift certificates, gift boxes, memberships, shop services, rentals.
Offer not valid on bicycles.
Offer not valid on boats.
Offer not valid on full-price skis, boots or bindings; snowboards, boots or bindings.
Offer not valid on GPS receivers, two-way radios, phones, personal locator beacons.
Offer is limited to stock on hand, is nontransferable and is not redeemable for cash.
Merchandise purchased with this offer is not eligible for the REI member refund.
Offer may not be combined with any other discount or offer. Limit one coupon per customer.
Cashier instruction: Apply 20% line discount to the highest priced item. Please refer to exclusions.