I don't have one myself, but I've seen interesting work done with them, ranging from very strange to tastefully artistic. Certainly appears worth the price.
Purchased one after reading the article about them in the B&W mag. They certainly deserve a place in the camera bag and I have made a couple of interesting images with the lensbaby on my EOS 3. My wife uses it more that I do with her colour work.
Like all special effect devices you have to be careful what you use it on. Recommended all the same.
And the Holga has the advantage that if you're shooting out of the sunroof of your car and a bird knocks the thing out of your hands and it gets run over by a Metro Transit light rail train, you're only out $12.