Yes, it works pretty well, but so do many things that diffuse light.
I agree, it is a bit cumbersome, and you'll get fairly odd reactions as to why you have a fishbowl on your camera.
If you want to try something, take a 1/2 gallon milk/water jug (not sure if that is a global sized product), and cut the bottom out, then cut the top to fit your flash.
If you are only playing around, this makes for a good start for a cheap DIY project.
Also, have a look at these:
http://www.abetterbouncecard.com/
http://home.comcast.net/~dougsmit/bounceflashtoys.html
http://www.listsanddiagrams.com/arch...0/diffuser.htm
There are also some interesting snoots you can build with a bunch of straws...
I also have a new light modifier I plan on testing/documenting and releasing some details on in the very near future - one that I haven't found anywhere on the internet.