Ruby, 8 chars
eval"<1+ Inspired by the Python answers
How it works
- eval can be used to execute an arbitrary string.
- "<1+ is the minimum set of characters required to build any string
A string in ruby can be built using the empty string as a starting point, and appending ascii characters to it, so for example:
eval ""<<111+1<<11+11+11+1<<111<<11+11+11+1 is actually equivalent to
eval ""<<112<<34<<111<<34 which evaluates the string
p"o" 