As has been noted in the comments and a FanShot, the 49ers have indeed signed quarterback Josh McCown to a one year deal. McCown was originally drafted in the third round by the Arizona Cardinals in the 2002 NFL Draft. He has played in 47 games (31 starts), completing 610 of 1,058 pass attempts for 6,584 yards, 35 touchdowns and 40 interceptions, while adding 127 carries for 569 yards and three touchdowns on the ground.
In eight NFL seasons he's played with the Cardinals, Lions, Raiders and Panthers.This past season, McCown played for the Hartford Colonials of the UFL, completing 114 of 202 pass attempts for 1,463 yards, 10 touchdowns and eight interceptions. So it looks like the 49ers did indeed get their UFL quarterback.
As Matt Barrows noted, McCown briefly played under Dennis Green who uses a variation of the west coast offense. That would seem to be the primary characteristic Harbaugh and Baalke were looking for as they scoured the trash heap for a third quarterback. McCown will likely be an emergency option if Alex Smith gets hurt.