I just recently got in an order of business cards from overnightprints.com and I'm totally in love with them. Not only are they great quality, but I used a coupon code and got 500 glossy cards for around $8 shipping included. Not bad! I fully recommend them if you're in the market for new promo materials.
I also just designed a cute little thank you card to include with my orders. Nothing better than a cute personalized hand written card to show my customers how much I appreciate their business. Some of them have coupon codes, so I'll randomly include them in some packages.
I used the new logo I designed too with help by the fabulous Bonnie Dee. She hand drew the lettering for me. I love it! Here's a sample one next to another business card. What can I say? I'm kind of in love with those cards.