You could always put a front wheel hub motor on it. It's been a long time since I rode one of those. If the pedals don't move when the wheel moves, yeah, it'd be easy to install. No problem. If it's one of those where the pedals have to move whenever the wheel moves then it'd be a little more of a pain to install. That'd be the only complication I think. I can't remember how those brakes work. I don't know if those kind of brakes would work well on a rear wheel hub.
I have a 24" cruiser bicycle and I'm wondering, can it be converted to electric, given it has pedal brakes as opposed to hand brakes?
As morph said yes you can convert it and many people have converted these bike and are very happy with them. However, if I were you I'd consider if I was really inlove with a single speed bike (I am assuming it is a single speed). Personally I think it would be a much better conversion if it were a shifter. You could look on Craigs list for a used bike or even look at a Wallie World bike.