I know you can buy LED lights sealed in plastic. They come in strips - some places have them for sale in pre-cut lengths, and they even come wired up for none DIYers. I'm not sure where I got mine (one of the guys at work bought some for a job we're doing and gave me 12 inches for free) but here's a web site that may help:
http://www.oznium.com/led-ribbon
I'll see if I can find out where I the ones I got came from. Hope this helps.