Just wanted to say that I have used these guys and I was very happy with them. They have lots of designs to choose from. Putting my words into one of their designs was good enough for me, but they will print your own art on labels also.
I had coasters made from this company: http://www.myownlabels.com/ML119.asp?fnColumns=4&AreaID=12
You can get 24 personalized coasters for $25 if you use one of their designs. You have to pay an extra fee (I think it is another $25) to use your own logo. Still a pretty good deal though...