Aquarium pumps are a type of diaphragm pump, it uses energy effectively, and really simple, can have enough pressure to push air through thin pipes, but they don't supply much air (3 liters of air per min, it was written on one of the battery powered pumps)
There are also Radial fans, that are good at pushing air through pipes and such, they are used in air conditioning systems, unlike axial fans (regular cpu fans) which aren't that good at pushing air through pipes.
So using a DC radial fan that is small enough to carry, a larger diameter air pipe, than splitting the air into smaller but four pipes, it's also not that loud when insulated, keep it inside a bag and it should be good.
You would look all futuristic, like an alien that can't breathe in o2, I wonder if there are air hoses in small diameters
http://www.jumpingcastles.com/images/air_hose.jpg but are like this, those circles prevent the hose from collapsing.
Yes you can just buy a bigger goggle and install a fan on it, but there are masks that cover up your face and can't be used just because they fog up, an external air supply can solve the problem, and cool down your face.
Also I tried using green gas to circulate air, but it burns your eyes :b
This is also another idea, using a gas like Co2 that aren't bad for your eyes, it can be used to replace the air inside the goggle, also it can be used to suck air from outside with the vacuum (think of air brushes, it sucks the paint out of the container by using a nozzle, the same type of nozzle can be used to suck air out of the goggle) but, you would run out of gas eventually, unless you have a bigger tank, like something 1 liter, or a special composite material tank (carbon fiber) thats 1 liter, and near 300 bars (300 liters of air) now that would last, but expensive, fun though.