I use these work lights for table top sometimes. Here's a picture of such a set up:

http://cg-area.de/lightset/aufbau.jpg

And here some examples of my first attempts:

http://cg-area.de/lightset/lights.htm

I'm not sure if these lamps gives enough light for portraits or shots of larger subjects.

However, take the advice of Alpha very serious.

Besides of electrically problems these lamps are getting very hot
and there is a high risk to burn down the house if you don't act very carefully.
Never let them switched on if you're not around and also make sure that there is a
fire extinguisher nearby, as you shouldn't extinguish electrically equipment with water.

cheers
Thomas