Saw this kind of neat LED light set while browsing their clearance section. It might make a nice accent light. Not altogether sure how bright they are, but there are also coloured cube ones available.
From their blurb:
This clear vase is filled with a string of 10 clear "ice cubes." Each cube contains a white LED. The lights are water-submersible, so you're free to add cut flowers and plants, or even create a small lighted aquarium.
10 LED-filled cubes.
Includes 24V 3W UL indoor DC transformer.
Each cube is 1 1/2" square.
Vase is 9 3/4" high, 4" wide.
16 foot, 7 inch long cord.