Mainly what I would be looking for would be a laser to point out stars at night. The blue ones make me drool!
In your opinion, how much power would I need for this to be effective, and would this require glasses for everyone looking at the sky with me? Or are they just worn in case they go directly into your eye? On the same note would it be possible to build one that only turns on while a button is currently being pressed? That way in case it gets dropped, it won't still be on?
For star pointing, I actually think the blue laser would be TOO bright, it would ruin the night vision.
I would recommend you the green laser, it's brightness should be just right, while also being relatively cheap and safe. Of course a direct hit to the eye could cause serious damage, but while pointing outside without any reflective surfaces around, some caution should be sufficient to avoid injury. Goggles would of course prevent any accidental exposure, but you also can't see the beam through them, so it wouldn't exactly be ideal to wear them while poiting at stars.
I don't have any momentary switch lasers in stock right now, unfortunately. Building one is possible, but few hosts support it, and I don't have any parts lying around, therefore it would take quite some time.