In addition to the many other benefits the Association for Computing Machinery (ACM) provides, I just noticed that they have added the O'Reilly Safari Bookshelf for their professional members. This, in itself, is more than worth the price of ACM membership. At one point, my company did a trial of the Safari Bookshelf that I participated in. I was really sad when they decided not to go past the trial. Now that I can get it with my ACM membership, I'm thrilled.
So, anyway, if you're in the IT field, it's even more advantageous to be a part of the ACM than ever before.