You can't buy a green diode like the reds & blues, There is a whole assembly of a 808nm pump diode, crystals, & lenses that have to be put all precisely in line or it won't give off 532nm of laser light. Google SAM'S LASER FAQ rob
It's all good, man. You CAN buy blue diodes now, they are commercially available in 473 and possibly even 488nm now. Really expensive and not being mass-produced, but very available. Green diodes, on the other hand, are not commercially available, because they don't really exist.
A review for everyone of what is *generally* available for handheld lasers/pointers:
Available in single mode diodes:
IR - 808nm, hundreds of mW in 5.6mm cans readily available.
Red - 650nm, 300mW readily available in 5.6mm cans.
Orangish red - 635nm, a few tens of mW available in 5.6mm cans.
Violet - 405nm, 200mW or even a little higher readily available in 5.6mm cans.
Blue - 455nm, 473nm, and other such wavelengths, variable powers available in 5.6mm cans, but only through special order from manufacturers at huge prices.
Available in DPSS, in order of decreasing availability/increasing price
532nm green
473nm blue
593.5nm yellowish/orangish (depending on your eyes, basically)
And others, but these are generally what you find in laser pointers.