Optical SETI has been talked about a while- in fact one major proponent of it was on the Zone many years ago...
http://www.coseti.org/

Laser Com is more energy efficient since the beam is so much more collimated, but as you point out, that makes it hard- essentially you only will see the signal if it is being intentionally directed at you.

An RF signal from the moon would cover most of the continental United States, the laser in LLCD made a spot a few km in diameter.

Accurately targeting a planet in another star system many light years away is not trivial matter- You have to know where it WILL be years later when your signal gets there... you could cover your bases by blowing up the beam divergence - making it less collimated, but then you are trading away one of the main advantages of laser com.

I can envision a laser being used as a beacon, "Hey look at me! I am obviously the creation of an intelligent species!"

Transmitting data beyond that gets tricky...

A 1 Watt laser at the moon transmitting at the Nd:YAG wavelength of 1064 nm with a divergence of 15 micro-radians would have a beam diameter at the earth of ~6km, for a power flux of ~35nW/m2 or 190 billions of photons per square meter per second- A telescope with 1m2 area is a good fraction of a million dollars.

Thats a lot of photons, but if you are trying to communicate at 1 Gbit per second that's only 189 photons per bit- and we haven't looked at the losses from the atmospheric transmission and your receiver and detector...

The moon is very close compared to the nearest star- the earth-moon distance is 1/24-millionth of a light year. The number of photons per square meter at earth will fall as the inverse square of the distance.

At 10 times the distance you will get 100 times less photons per square meter.

At 1 light year you will get just 0.00034 photons per square meter- that means you would need a 30 m diameter telescope just to have a good chance of a single photon from your 1W laser at 1 light year hitting it.
You need a much larger telescope if you want to pick the signal out of the noise...

If you transmit using a diffraction limited beam transmitted from a telescope like the Keck with a divergence of 64 nanoradians you get 18 photons per square meter per second on earth (but the spot diameter is 600 million meters- earth moon distance is ~400 million meters, so you have to point it very accurately at a point where the earth will be 1 year in advance.)

That is 1 Watt at 1 light year using a perfect 10 meter diameter telescope to transmit the beam.

That same transmitter located at Alpha centauri would get you ~1 photon/second per square meter incident at earth...

The flux will scale linearly with the transmitted power, 1/r^2 with the distance- and 1/divergence^2

So it is possible, but it rapidly becomes very expensive and difficult to do- especially if you want the flux to communicate a good number of bits per second.

A megawatt laser transmitted from a 10m telescope at alpha centauri would be a pretty good start.... and the bigger the telescope on earth to receive it the better....

But the main problem is that the ETs would have to target us very precisely... so they would have to know we are here, and know exactly where our planet would be years in the future.

Not impossible, especially if you assume advanced ETI technology...