Centerpiece idea or ambiance
Zigidoll posted an entry on her blog a little while ago about dressing up lampshades, which made me google for more info. I found this seller on Etsy, and thought gee, that would be a really cute idea for dressing up those mini-battery operated lamps. I can't find a photo of the lamps I'm thinking about, buy they are the size/shape of a welcome candle, and have a small lampshade that goes with them.
I think that if you get the ones with white lampshades, you could cover the shades with appropriate fabric (lighter/thinner fabric will allow light to shine through better) or paper printed in your choice of pattern. If you want an image(or table number) to appear only when the lamp is on, you can print it in reverse on one side of a sheet of paper, then apply that to the shade face-down, it should only appear when the lamp is on.
This would be a good option for those who don't want/can't have candles, and can be paired with other things, like books, vintage type games, and a nice way to disgiuise the fact that your candles run on batteries.
These would also be handy where a little extra light is needed, but you don't want to ruin the mood, like the guestbook table(with pictures of Poe, Mary Shelly, other spooky literary persona), around the bar(with interesting potions printed thereon), or just some nice black lace