I can see by my Blogger Stats that the Kobo Coupons posts are still pretty popular. The only problem is, they're old and expired! Here are some new ones for you:
Get $1 Off select Kobo eBooks - Kobodollaroff Valid until August 31, 2011
20% Off Kobo eBooks with code "June20off" Valid until December 31, 2011
To use the coupons, just click on the link. That will take you to the Kobo site where you can choose a book. When it's time to purchase your book, enter the code (either Kobodollaroff or June20off) in the promo code box and apply it to your order before you finalize your purchase.