Vimeo member ephisus uses several strings of Christmas lights wrapped around a wreath frame to create a continuous ring light source. There's a definite catch light in the subject's eyes that smaller diameter ring lights have a hard time achieving (unless you're super close). The trick to making these catch lights smaller or larger is to move it closer or further away from the subject. I like the ring light effect, but some people see it as 'unusual'. If you pull your light source a bit further, you'll just get a clean round dot. Simple build, no soldering, with an estimated cost of about $25 dollars. [Thanks Joel]
These type of stringed bulbs are getting harder to find now that LED XMAS lights are inexpensive to make, use less power, and generate no heat. Check your local hardware stores, but online i've only managed to find two that might output enough light.