Bit Switching - How?

[Ralph Wirthlin]

This may have already been asked, but ...

Does anyone know of a *very fast* way to swap bits at some location n 
between two separate bytes b1 and b2?

	       offset
	      3 2 1 0
	      =======	
e.g.    b1 -> 0 0 1 1 
	b2 -> 1 0 1 0
	
swapping bits at offset 3 would produce

	       offset
	      3 2 1 0
	      =======
	b1 -> 1 0 1 1
	b2 -> 0 0 1 0


Thanks for any help you can give.

-------------------------------------------------------------------------------
Ralph L. Wirthlin          	    |  "Who knows where madness lies ..
EMAIL:wirthlin at uvm-gen.uvm.edu	    |   To surrender dreams, this may be 
USMAIL:  BOX 125  Newport Ctr., VT  |   madness .. too much sanity is madness,
				    |	but maddest of all is to see life as
				    |	it is and not as it should be"
				    |              - Man of La Mancha	
-------------------------------------------------------------------------------