Do you mean to latch an analog voltage?
http://www.analog.com/static/imported-files/data_sheets/SMP18.pdfIs this close?
Digikey has them in single quantity, but they are pticey @ $16.
I think they are like an analog multiplexer that sets the addressed output pin to the value of the input instead of passing it through. You want to set an addressed pin at a voltage and hold it at that voltage? Then a multi channel DAC is what you need?