First of all, let's talk SLIMMING
Brand "caffeine stockings and shape wear" contain micro capsules of caffeine, which is known to fight cellulite and firms skin (most anti-cellulite creams have caffeine in them). Right now they are sold in the UK (but you can have them shipped to the US)
Now, onto tanning tights (what a genius idea!) Skinkiss also makes a pair of stockings that contain the DHA chemicals in fake tanners. The first time you wear the tights, they tan your legs (as shown below)
After that initial wear, you wash the tights and wear them as regular stockings (read: they only tan you once)
You can buy them here for about $20:
Very interesting, and worth trying!