“If you want to preserve real photographs for posterity, get them laminated. Without some environment protection they will degrade over time and with handling.”
Another thing to do is to digitize them, then put the entire collection on multiple high-quality CDs, hard drives and thumb drives. Spread those storage devices out among many people in many locations, so that if some are lost or destroyed, the family still has them. Putting them on the web (as part of an Ancestry tree, for example, or a family website with restricted access if you prefer) is an additional safeguard. WRT the electronic copies, I like to wrap them in bubble wrap, then in aluminum foil, and then in another layer of bubble wrap - that way any electrical discharges (including an EMP) will not destroy or scramble the data.
Honestly, laminating them is the worst thing to do to preserve photos.
Photos properly mounted on paper and kept out of the horrifying environments of heat sun and humidity, they will hold up for centuries. Literally.