I decided to get this just for the heck of it:
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item
=7385606235&ssPageName=MERC_VIC_ReBay_Pr2_PcN_BIN_ IT
It was 10 euros (12 bucks) and he'll ship it to the U.S. for another €7
I wouldn't use it alone. It has this bright piezo midrange sorta like old Barcus Berry's, but it complements my Schertler nicely. I think it would work well for people who get a good bottom but want more woody mids, as was my situation.
There is some english on the site. It seems to be intended for making short tracks for your cellphone or something. There is also a mono version. I actually pulled the stereo version apart and have one piece stuck on my bridge just above the heart, and the other on my wife's viola. I stuck it on my fender just in front of the neck pickup and liked what I heard too.
The thing is very delicate. You have to be careful how you position the wire, and it is not hum-free, but does have a lot of gain. It likes to be plugged into a Fishman preamp.
If I get really ambitious I'lll put up some mp3s.
I don't know the guy, and have no personal stake, just thought I'd pass along a tip! (not responsible for misuse, abuse....!)
Robobass