It's pretty fucking wierd. You have to eat a lot of it and it tastes nasty as fuck. It feels kinda like a marijuana high and it lasts for a loooooong time, including the hang-over the following day. At high enough doses you will start tripping. Read about it on erowid, they have plenty of experience reports about nutmeg.
It is a pretty rough hangover, much worse than alcohol IMO. You kinda feel like you've been poisoned, maybe that's because you have been poisoned. It's still a rather nice buzz, though.
One problem with the use of nutmeg as a drug is, that you can get problems when you consume it in normal doses (in food) later. There have been reports of allergic reactions too.