Back when I was a freshman, I was invited to join, but threw the envelope away because there is no real credence to the organization, and I don't think its worth the money.
My brother said the same thing when he was invited to become a part of it.
I think I can volunteer and do important things without the organization.
Also there are other honor societies if you want them.
However, I second the notion posted by LP1CW.
As LP1CW said, anyone with a good GPA can get into honor societies as long as they pay their dues. It is much wiser to do things that set you apart.
For instance, don't think that being a club president is going to carry more weight than a person who spent several hours volunteering and actually gaining good patient experiences.
But at the same time, don't think if you volunteer x hours of volunteer service that makes you better than the person that had to work to pay their bills but didn't get time do much volunteer work, and so forth.
Everyone has their good and bad qualities, but ultimately its what makes you different from the rest of the applicants that sets you apart.