Lenovo.com again takes 20% off its selection of ThinkPad X-Series Notebooks and Tablets, this time via coupon code "USPANNIV1031". It's among the best coupons we've seen on these ThinkPad laptops. This coupon stacks onto the ongoing 15th Anniversary Sale, which already takes up to 25% off. With free shipping, some models are at or near lowest-we've-seen prices. Deal ends today.