Sun Mar 10, 2013 12:55 pm
No. It can control a motor but it should be independently powered.
The 5V supply is derived from the microUSB which is used to power the Pi and anything on that line. If the Pi were to take 700mA then you're left with the remainder, so for a supply rated at 1A you'll something like 300mA.
Additionally the inductive load of the motor can generate larger spikes on the line during start/stop operations on the motor. So you'll need ensure the line is well protected for these back-EMFs, even if you were sure the motor would not draw too much current.
Please search the forums, read the guides and HowTos and take a look at, and study, the MagPi magazine where sound advice is given.