N2 is used in beer brewing, to get a better head on the beer. (Or so they say; I don't drink, so I don't know for sure.) Hence the cover story of "Max Dog" brewery supply N2 tanks.
It is also used extensively for welding, as a shielding gas. (I believe it's especially useful when welding plastic, but I don't know that for certain.)
In all honesty, I use it in my woodshop to "headspace" the partial cans of paint and varnish: flood the partial cans with inert gas and the remaining paint won't react with the air, skin over, and go to waste. When some of the paints I use cost $250+/gallon, or $35/qt, it makes a lot of sense to buy a tank of inert gas. This is the excuse I used to buy a 40cf tank, to go along with the 20cf of Ar that I already had on hand. The guy at the welding store didn't make any more fuss than to say, "you learn something new every day!"
As Stryxmain says, make sure you've got the right sort of regulator. The critical element is that it'll need to give you a flow of 15Lpm, either through click-style settings or with a flowmeter that reads in Lpm. Some of the welding regulators intended for low flow welding only read in Cfh, which typically means they won't give you a high enough flow to work with an exit bag, so be sure to check.