4,5V 650nm laser, will I need a driver?
Unforrunately, no -- not if you want them to work correctly.

Laser diodes are somewhat similar to light emitting diodes (technically they are....) in that they have a particular diode I-V curve.

If anything, you would at least want to use a LED driver if not a constant current source. In that case you could wire a few in series.

Without a datasheet for your lasers, design is going to be a bit more seat-of-the-pants.

I recommend http://www.linear.com/product/LT3598 as a laser driver. It will require circuit design, soldering, and more parts I'm afraid. Still if you work hard it will make a great costume @ the end of October!