I had to lay it on its side on the bottom on a storage shelf. The only drawback is having to tilt it upright every now and then to purge the tank. My moisture filter needed to be re-adjusted to properly work as well.
I ran a hose to my bench and have a curly hose hooked up to it. Its soooo nice having on-demand air at the workbench without having to turn the compressor on and hang out for it to reach pressure. The only drawback is that is a bitch to chuck into the back of the truck if I want to take it somewhere.