Just a quick 'thank you' to the forum, I got my Arduino powered laser harp fully functional
Quick demo here:
Thanks again!
Steve
wow - that's too cool 
Thats impressive!
Do you have a description of how you build it?
The electronics i can probably understand, but how about the optics, do you use multplie lasers or beam spilitters.
How do you detect that a beam is being broken by your hand.
Do you only detect breaking a beam or also distance sensing of the hand ?
Hi,
Quick update - I put together this page to hold info on the project
also:
I'll be posting schematics and code soon
(I was mentioned in the Makezine.com blog yesterday - I got 12 emails and 2 phone calls from people asking how to build one - so I thought I'd better get the site up ASAP.) 
That's a very cool harp!
I'm also building a harp, but it is a framed one. I've finished a rough 'Blue Peter' three-string proof of concept using a single red laser pointer, a diffraction grating to split the beam and three LDRs to sense the beam. It's ugly but it actually works really well.
I'm building proper octagonal frame for a ten-string 'mesh' style harp - two sets of five strings running perpendicularly across each other. The idea is you should be able to play up to four note chords with two hands... and it's a bit different. I'm just waiting on the LDRs I've ordered, and I should have a nice new instrument!
I'm using ten separate 1mw laser pointers, because that's all I can afford for this project, so I'm expecting to have to use a lot of smoke for it to be at all visible...
I'd love to build a scanning frameless harp too, but one look at the cost of the scanners sent me running...
One idea, maybe you could couple your 'brightness' sensor with an IR distance sensor, to get more reliable continuous controller info dependent on your hand position?
Dave
That looks stunning.
Has anyone got a link to a suitable laser module?
Thanks,
Mike