LED candles don't put off heat, you can get them big, small, and even submersible ones (though a bit of weight added and a piece of tape over the bottom of a small normal LED tealight makes it submersible. I actually tested that theory using one of mine, so if you bury/disguise them you can have them glowing through crystals, water, etc.. I'll post a link if I ever decide exactly what I'm doing with mine. This is what they look like, nothing special at first but you can get wax-coated and rose shaped ones as well:http://www.100candles.com/Images/Items/rechargeable_led_candle.jpg
Also, Michaels sells a fantastic little device I'm playing with right now. it's a floral light, tiny bulbs about the size of an LED, though their not LEDs.. Their battery operated, just like the LED candles and come with several ends you can stick into flowers (I'm doing paper flowers so that's of interest to me) or run through gauze or some such.
They look like this:http://www.residential-landscape-lighting-design.com/store/images/AL_xll_10bat.jpg
You can get long 30 foot chains, or ones with individual ends. The possibilities are fantastic, and both these options mean you run a lot safer than having a lot of real candles. Because, let's face it, fire will generally bring out the stupid in at least one guest, whether it's a singed drapey sleeve or just spilling hot wax on a nice tablecloth.