I've considered numerous amplifier IC's, but I settled with the Texas Instruments' LM4811. The IC's small footprint and low number of external components required made it the perfect candidate for a size restricted design. The LM4811 also featured digital volume control, which means I won't need to include a clunky potentiometre to provide volume control! However, TI suggests using a microcontroller to handle the digital volume control. Microcontrollers are expensive and need to be programmed, so I came up with an alternative, which I will explain in a later log.

http://www.ti.com/lit/ds/symlink/lm4811.pdf