best quick&cheap power supply inverter
I use the Analog Devices ADM660 which does about 100mA. Wasn't concerned with the switching noise in my application since I followed it with an LDO.

You could check out the LT1046 which also does 100mA. The ICL7660S looked interesting.

Your best bet is probably the Linear Technology site. If you can get one of the 100mA
devices you may able to get an adjustable LDO to remove the switching noise. 
For the LTC660 the graph show -4.8V at 30mA. That gives you a few hundred mV
of dropout at 30mA.