Here's my latest project. It was super easy to do and cost next to nothing.
This works great for nano tanks. Recently Home Depot came out with a 6500k spiral bulb, either 13w or 15w option, so I knew it was feasible to use that bulb for a building project. Cheap, works great for plants, intense lighting. Some light is lost due to weird shape of spiral bulbs causing restrike, but can be partly compensated with a good reflector.
For canopy, items required:
Some particle board and wood panels
Some wood glue, some nails + screws
Lighting system:Two 13w compact fluorescent spiral bulbs, 6500k (I bought at Home Depot, 6 for $20, so 20/6x2 = $6-7)
Extension cord ($5)
Plug-in socket, medium base ($3.28 + tax, you can substitute one with a dial switch as an extra feature. It costs more and I already use a timer, so no point)
Twin light socket, medium base ($3.58 + tax)
Some sheet metal ($3-5, I bought a metal air duct part and use the material)
Extra: some mylar sheeting (usually bought in bulk, but you can find it inside those shiny helium ballons or the inside of a chips bag.
Add it up, it should cost you about $20-30.
Basically, build a canopy, cut a hole in the back to fit the plug-in socket through. Build a reflector, glue some mylar sheeting on to make it shiny (you can substitute mylar with white gloss paint).
Screw in the 2-way light socket into the plug-in light socket, screw in the bulbs into the 2-way light socket.
Plug into to extension cord and there you have it, 26w of nice light.
If this doesn't work, you can always buy a Home Depot full spectrum power compact desk lamp.
Edit: I also forgot to include the fact that there is no wiring invovled at all will be a big plus for those who aren't comfortable messing with electrical wiring.