Anyone know of a 2-1 mux chip?
There are several common logic ICs available in small/single versions today. The HC157 has a two-input version in the 74AUP1G157. This is a basic 2-to-1 multiplexer. The 2G157 Brian mentions in his answer has an additional enable input and complementary outputs.  

As far as I know there are no multiple 2-to-1 digital logic multiplexers. But there's no reason not to use several 74AUP1G157s on your board. The 1G157 is available in a SOT1115 package, which is less than 1mm\$^2\$.  

  

Three or even four of those are smaller than a typical 14-pin SMT package. May not be the easiest solution for DIY, though.