A few weeks ago I bid for a vocal harmoniser on eBay. 
I didn't win it - but was fascinated by this little vocal fx pedal. 


So I checked out a few reviews and videos such as this one:


and this one:


In the end I decided that I had to at least try this thing... so I bought one!

Since then I've played live with it three or four times just performing solo with an acoustic.  The response from the audience has been fascinating, and really positive.  A few people have said that they MUST get one (but nobody else has so far).

Has anyone else got any experience of vocal harmonisers used live?

All I have to do next is find out how to set the thing up to record only the harmonies. 
I like a challenge!
 

Cool bit of KIT
Strictly for solo live vocals.

I love the first video when the voice is made lower, wow very convincing - and yeah would be interesting played to a live audience... - I wonder how that effect would sound with a female singer, or vice versa a butch male vocal turned into a sweet female..

I think you're probably right Denis - it is, after all, called the "Vocalist Live" pedal!  Obviously you can record with it, but not the way that I like to do my recordings (guitar first, lead vocal second, harmony 1, 2, and/or 3, then additional instrumentation if there is any) - this is very much a one take gizmo, and that shows in the videos.

I've played about with some of the vocal effects (naturally) and they are fairly interesting, but I'm not sure that any of them really have a place in a live show (other than to make people notice the pedal!).

I've had a Digitech Vocalist VHM-5 (I bought it in 1993).. Mine is not as well-developed as your's - but I have used it both live and for recording (some of which has been uploaded to this site). I don't have the ability to simply track a guitar (I have to control mine either with a keyboard provided on the device itself or I can control it using any midi-capable keyboard). It's tricky to use live (the harmonies can sound kinda "Darth-Vaderish" so I have to bring them down in the mix somewhat) and you can definitely hear a synthetic quality in recordings, too. But I've always had a liking for harmonies and never could find singers willing to work them out very well. I've also used it to supplement weak "real human" harmonies.