解：∵$|a-\frac {1}{2}|+|b+\frac {1}{3}|+|c-\frac {1}{4}|=0$，且$|a-\frac {1}{2}|≥0$、$|b+\frac {1}{3}|≥0$、$|c-\frac {1}{4}|≥0$
∴$|a-\frac {1}{2}|=0$，$|b+\frac {1}{3}|=0$，$|c-\frac {1}{4}|=0$
得$a=\frac {1}{2}$，$b=-\frac {1}{3}$，$c=\frac {1}{4}$
则$b-a+c=-\frac {1}{3}-\frac {1}{2}+\frac {1}{4}=-\frac {7}{12}$
