I was going to post as someone else did, signing up for their email newsletter is a great business decision. I often get free products from them as well as signing up for their surveys and telling them what new materials I would like to personalize, they truly listen and one item that I (and I'm sure hundreds others) mentioned, was up for sale a few months later and I was able to get it free!
The best thing I think is you can upload your own designs, usually for a one-time upload fee of about $4.00, and then use that design on anything else on their website! If you're lucky, you might be able to catch a No Upload Fee weekend! They just had one in February 2011.
Overall I found their service great, shipping can be slow sometimes, and their quality has always been great for me! I've gotten almost everything on that website.
Pens look good.
Tote bags are large.
Paper pads look good.
Address labels are nice.
Business cards are durable and great printing.
Postcards were nice on cardstock.
Keychains were kinda large, but I got them right after they came out, may have been improved now.
Mugs look really nice.