How and where can I buy some NEM?
You can get on the waiting list
here. This list will be used to bring the total number of stakeholders up to ~3000 people after the removal of sockpuppets.
Other than that, you'll have to wait till launch late May I'm afraid. I know some people are selling their stakes (by selling their BTT account), but I'd wait a couple of weeks until the final contractual stakeholder list has been released before doing this.