I got one of these for $2 at the dollar store and it was terrible terrible terrible.
http://www.bestbuy.ca/en-CA/product/.../10154011.aspx
Can't believe they're charging $20 for this, anyway, the problem is the light shines directly ahead out of the led, not down onto the reader. So I put a bit of aluminum foil tape over the top and front of the light. Now it's absolutely perfect, better than any of my other lights and much smaller. Just don't pay $20 for one.