Negative Voltage Rail

I have some filters that I'd like to power with the arduino, but they require both a -5V input and a +5V input. The +5V is easy, but what's the best way to get a stable -5V out of the arduino? I thought about using an inverting op-amp - will that work, or is there a different solution I should be aware of?

Google a "voltage inverting chip" these have a built in oscillator and capacitive ladder. The only problem is that the current from these chips are a bit limited to about 50mA.
The Max 232 chip does the same trick to generate the negative voltages you need for RS232.
Look at:-