This is a very limited offering, but if you are looking to get a heck of a deal on a tablet pc, then check this out:
$400 off web-only coupon for the purchase of an HP Pavilion tx2500z Notebook PC at the HP Home & Home Office Store + FREE 3GB memory upgrade (from 1GB). Coupon excludes HP Pavilion Mini 1000 and Special Edition Notebook PCs. Coupon code: NB4398. Offer limited to the first 1,000 coupons redeemed or 12/28. 1 redemption per person or address. Not valid with other promotions. Restrictions apply. Not combinable with instant rebates.
UPDATE: This offer has now expired.