Its kind of one of those things where the only limit to what you can do is your creativity. If you have a more powerful laser like a 1 Watt then you could pull off some neat tricks like lighting a candle from across the room. Or you can buy a lot of small mirrors from a craft store and place them around a room to create cool beam patterns.
Just remember these rules if you do buy a laser of that power:
-Buy some quality laser safety glasses! These usually cost at least 30$ but your eyes are worth it!
-Never shine your laser at airplanes, cars, people, or animals! Not only is it dangerous, but you can go to jail!
-Use good common sense! Lasers can be fun, but a simple lapse in judgement could cause you or others harm.
I know these may seem obvious, but theres a surprising number of people out there who have bought powerful lasers and end up doing stupid things by showing off.
Be safe, have fun, and welcome to the forum!