Good ideas often pop up simultaneously in different places, thought up separately by different people (think Charles Darwin and Alfred Russel Wallace...though hardly anyone remember poor Alfred). We remember seeing Domestic Construction's Coffee Cup Lamp, a pendant style lamp available on Etsy awhile ago. And today over at Nerd Approved we spied a similar idea from Connox...The 156.00 € ($200) light is made of genuine porcelain, but we don't see any reason you couldn't fashion something similar using some IKEA LACK bookshelves and your own choice of plastic or wood drink ware (making holes in porcelain is no easy feat) with a handy glue gun. Small bulb LED lighting systems meant for shelving and cabinets would probably be the most energy efficient choice and would prevent too much heat buildup, eliminating heating up any the adhesive you'd use to create a similar setup. And you could equally exchange out tea cup with bowls or other shaped "shades".
The only problem with this is we'd always be craving a cup of coffee each time we'd switch the light on. Can we get this in decaf?