I picked up a Meike ring flash off ebay last week.  Got it from Cowboy Studio for $36.  Has to be the best $36 bucks I ever spent.  Its LED, which I am loving the LED lighting.  Its simple to use.  Has the ability to stay on constantly or fire with each picture.  The refresh time is almost instant.  I was shooting off pics at speeds around 400 and it was firing every time.  Didn't notice any sync problems either. 
I have also tried using it for non macro shots. 
I can't recommend something like this to have in your kit bag enough.

Get me one too, Doodle!!  LOL!

This is the ebay link
http://www.ebay.com/itm/170781324922?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Their website is www.cowboystudio.com
But the ring flash is twice as much on their website.

Thanks pinecone, they're on my list now.
 It looks like they have several so no hurry.

I'm not big into macro but for the small price and the small number of shots that I do take, you have talked me into it. Now you should be getting a commission.

I'm not big into macro but for the small price and the small number of shots that I do take, you have talked me into it. Now you should be getting a commission.

I've actually played around with using it for more than macro as well.

I was actually just going around the house playing with it taking pictures.  Unfortunately I can't post em because the house is a mess and the wife would kill me. 
Now, of course, you don't have the ability to bounce it.  IF, its mounted on the lens.  This particular unit doesn't have the ability to mount the ring separately, but you could probably rig something up.  The control unit does sit in the camera's hot shoe, so I don't see why you couldn't use it with a remote trigger.  (Haven't tried it yet.)  One disadvantage I do see, if the surface is shiny, you see the ring in the reflection.  But that could be photoshopped out I suppose. 
The other thing I've read they are great for is video. 
One BIG advantage, is your light source basiically comes from the lens.  With a flash unit mounted on top of the lens, you have the potential to get a shadow from the lens, not with a ring flash.  Your camera lens is pointed directly at your subject, and so is the light source. 
This particular unit has the ability to increase or decrease the intensity of the light output.  It also has a constant on feature.  Which is kind of nice as it helps with the auto focus in low light.  I find it works a lot better than the beam from a flash. 
This unit is also an LED.  So technically its not a ring flash, its a ring light.  But it will "flash" on when snapping a picture.  I like the light from an LED.  Plus, think of how long your batteries will last.  There are more expensive units, when I was looking, I saw some that were easily $500.  They have a true flash on them. 
I've also seen accesories, like diffusers, color gels, etc that you can use.
I haven't given up, or will be getting rid of my external flash.  There are definitely times for both. 
But when you want direct, white light, these are the way to go.  If you ever plan on listing items on ebay, you need this flash.  I've sold literally tens of thousands of dollars of stuff on ebay, and I can tell you, a bright clear crisp picture gets better results every time.

Just received mine.  I've never taken a macro photo in my life, but for that price...