To go along with my new DC Lightorama board, I pre-ordered some MR-16 32-LED bulbs. 8 each in white, red, blue and green. The specs are here.
I hope to be able to replace the 16 halogen flood lights I used last year, this would be a huge power savings and the LED bulbs are very cool!
I will have to make my own MR-16 holders; so here are a couple of ideas from other people:
Off the shelf:
http://www.superbrightleds.com/cgi-bin/store/commerce.cgi?product=MR16&keywords=&cart_id=3551995.5713&next=50 (OK this is indoor, but one several steps closer than the DIY links - look for the plant up-light).