Good friends/family may want to get you something. Let them! And I like the previous advice of tucking those away to be opened later, so that folks who simply come to celebrate with you do not feel as though they've done something wrong. For the masses...no registry! "No gifts, please" would be the proper statement on the invite.
Here are some other tasteful ways I've seen this handled
1. Choose a charity to be the benefactor of your celebrants generosity. In lieu of gifts, please consider giving a donation to (xyz charity) in our honor. OR
2. Have your children send out the invites. Have them request small, optional monetary donations for a "money tree" intended to send you on a mini "2nd honeymoon"
3. Depending on the timing in the Fall consider collecting school supplies for needy children or food for Holiday food baskets or toys for tots, etc.
4. Tell your guests that a scrapbook will be on hand. Tell them their "gift" to you would be a (or some) family photo(s) that you can put into a memory book. Provide materials at a table and, instead of signing a typical "guest book" each guest would construct a scrapbook page for you. They can be encouraged to answer simple questions: how they met you, how long they've known you, their favorite memory of time spent with you, etc.