AOPA and helicopters
Being a tight bugger by nature I was initially doubtful about what AOPA actually do but having been a member for the past few years it is pretty clear that they are extremely politically active in lobbying governments and aviation authorities on behalf of GA.
They are also kept fairly busy representing and advising pilot members who find themselves on the wrong side of the authorities.
Membership costs peanuts and is well worth it IMHO, I also like the (free to members) magazine. It is far more focused on the business end of aircraft use than many others and is usually interesting reading.
BTW my annual membership is almost completely paid for by the fuel discount I get through AOPA every time I fill up my Mooney at Jersey.
SB