Green Lasers ? What are the advantages over red? Intensity, Etc?

Green falls in a portion of the visible spectrum that is easier to see, so if you have a red laser and a green laser of equal power, the green laser will appear brighter.

The down side (and I'm no expert) is that green lasers are not from green laser diodes... they have multiple diodes, and do some funky phase shift/cancellation business to make green out of un-green laser light.  This means more heat, and shorter battery life.  But I don't know too much about all that.