For all intensive purposes, yes. There's a website called "in gender" that tells you all about the high-tech (through PGD/IVF or Ericsson/IUI) and low-tech (Shettles/diet) ways of influincing gender. PGD is probably the best bet since only the desired gender embryos are transferred.
Let me tell you, from my own personal experience, there's something to the Shettles method. With DD, we did-the-deed a few days before ovulation, we have a DD. With this pregnancy, we wanted to up our chances of conceiving because we were having fertility issues, so I used my clearblue fertility monitor, and we did-the-deed on ovulation day-- and we're having a boy. I think there's a lot to this, there is actual "science" behind it!