Low voltage drop transistor/mosfet switch - 3.3V 200mA
A FET should be able to do this.  Of course without knowing how much voltage drop you can tolerate and what the load current is, it is impossible to say for sure.  You can easily get a small FET that goes down to a few 10s of m&Omega; in a small SOT-23 package.  Check out the IRLML2502.  You can get lower on resistance by spending more money, like getting a more exotic FET or putting multiple of them in parallel.