I made my own tins, based on the instructions here. I had my design printed on vinyl at a local shop, and they applied it to sheet metal I bought from onlinemetals.com. I used a sheet of stainless steel with a sheet of cold-rolled steel behind it for magnetism, but you could probably just use the regular steel by itself with a bit of polish and anti-rust coating. I got the labels from LabelsByTheSheet.com and printed them at work. I made the frame with some moulding and spray paint from Home Depot, but you could also buy a frame from a craft store.
EDIT: WOW! I never expected to be featured on the Instructables homepage, let alone ThinkGeek's Facebook page. Thanks to everyone who "liked." Due to the overwhelming cries of "want!" I'm temporarily taking down the high-res PDF until I figure out if it's feasible for me to sell and market these things myself. If I can't figure it out in a few weeks, the PDF will come back for all you fellow DIYers.
Right now I'm keeping track of comments for missing ingredients or suggestions on arrangement. Yes, I know salt is not technically an herb or spice, but can you think of anything more "elemental" to cooking? I also didn't include some common ingredients like fennel, vanilla, capers, mustard or mint because I usually use fresh instead of dried. I chose clear tops because it looks cooler, even if it's not as good for the herbs.
UPDATE: Thanks to everyone that's shown interest in this! I'm hoping to start a Kickstarter campaign by the end of April, but I need to nail down suppliers before I know how much money I need to raise. Finished products will be available as rewards for either a discount or at least free shipping. There will be three different sized kits and KS contributors can vote on which spices are included. There will also be options for customized orders or individual add-ons. I wish I could move faster on this but I have a job that keeps me pretty busy. Stay tuned for updates!
UPDATE 2: I am still working on this! I've got prototypes of four different sized kits that should be finished this week. I'm hoping to start my Kickstarter campaign soon, but there's actually a patent on magnetic spice racks. I'm trying to contact the patent holder and work out a license agreement. If that doesn't work out my backup plan is to sell prints of the table and customers will be on their own to buy or make the tins.