For all of you holography buffs, here is a dirt cheep wavemeter
http://cgi.ebay.com/Candela-Corporat...item53de9305c4
If i actually needed a wavemeter I would grab it in a heartbeat, but at the moment another project is exactly what I don't need
Looking from the pictures it looks complete, although the dual output beam is a little worrysome (it is probably in dire need of alignment), and these aren't exactly the most complicated devices on the planet so it should be possible to get running.
But if you want to know what the mode pattern or your coherence length is, that is the tool you need.