Liquidorb, before you get carried away with shining lasers onto mirrors you should seriously ask yourself: how much do you value your eyesight?
Looking directly into a laser, no matter how small, CAN SERIOUSLY DAMAGE your eyesight.
And, what you are planning, is just asking for such an event happening.
Another fact, you actually cannot see the laser beam, just the reflection of it where it strikes a surface, unless you have it in a smokey room where the laser beam strikes smoke particles. Or outside, with cloud, mist, etc. getting illuminated by the beam
If you are old and mature enough to experiment with lasers I would suggest you get a low powered laser pointer. You must NEVER point it at any eyes, even if they quite far away. You must NEVER point it at a mirror, it could be your eyes that get hit.
Some may say that laser pointers are not focussed nor powerful enough to do eye damage, well, perhaps, but it is good pactise to use common sense and care with ANY laser product.