http://www.devicecraft.com/haefcuse.html these are pretty neat current sensors. i have 2 of them, they even provide schematics and values so you can re-scale the output to whatever you want. pretty neat, or you can wrap a wire inside them multiple times to scale the range. all they need is +5 volts, ground, and the output is an analog output that varies between 2.5 volts and +5 or gnd. just keep in mind that if you are measuring current in an AC line, the current is going to be oscillating at whatever operating frequency you're working at, so if you just take current measurements whenever, you will get very wrong values. (also note, i am not affiliated with that company, i just like their product)
