I don't think much of virtual ground circuits, but I drew this:-
As drawn it draws just 1.4mA, has an output offset of 6 nanovolts, and an output impedance of ~0.1 ohms. Build it with the LT1097 shown for the best performance, pretty much any complementary NPN/PNP pair will do, the bigger the beta the more current you will be able to sink/source (within the dissipation of the transistor). You could use the 2N3904/6 for modest currents, they have loads of gain and are pretty fast. You can even null the LT1097 offsets with trimmers.
It shows 2 big caps, dimension these at your discretion, you don't want the leakage currents being the biggest current drain.
The 2 voltage sources on the diagram are just for simulation of the worst-case opamp input offset. The LT1097 is ~$5 a throw, not cheap.
If you build it casually with an LM2904 use 1 ohm buffers instead of the 0R1 shown, you'll get worst case current draw of ~3.4mA. The LM2904 is a dual, ~U$0.40, and you might get away with reducing the buffer resistors to 0R1 if you measure the voltage drop across them, because it's unlikely that the input offsets of 2 amps on the same die will have an adverse coincidence. If you use the 2N2904/6 you can probably build it for less than a dollar.
If you don't care about the current drain as when using a wallwart, use a NE5532, I buy them here, 50 for $10 http://stores.ebay.com/Tayda2009/_i.html?_nkw=NE5532&submit=Search&_sid=872591586. Quiescent current will go up to 10~12mA. Then if you can find a 4A complementary transistor pair with beta of 100, the opamp is good for 40mA.
All round it just blows away pretty much anything else I've seen for headphone-sized (and somewhat larger) currents...
Edited by wakibaki - 4/16/13 at 4:46am