Yes you can do it easily if you keg.
usually you get as mix of around 60/40 nitrogen/CO2 (or the other way around).
i got a cylinder of it about 7 years ago, but from memory it kinda smooths the beer out as used in aussie guinness etc, giving a creamy feel for UK beers.
it was nice in lots of the beers, but i ended up getting sick of it, didn't finish the cylinder and just got it refilled with CO2.