No matter how much life changes, we seem to remember our close friends from elementary school. Old childhood friends, though, lose contact with one another as they go off to school, move away, launch careers and start families. There are number of free or inexpensive ways you can use to find your long lost friends from elementary school. All you need is the willingness to do some legwork and Internet access.
Start with social networks like Facebook. Most social networks have an "alumni" function that lets you designate yourself as a graduate of a school. Although high schools and colleges are more common, some elementary schools will be listed. If your school isn't, type a friend's name into the search function and see what comes up. Old friends could be on your social network and you don't know it. LinkedIn is another social network that generally includes education information that could help narrow the search for classmates that attended the same school as you.
Use a search engine like Google. To narrow the results, type in the friend's name and the state where your elementary school was. Many people have an Internet presence, like a personal website, or have been mentioned online. In some cases, your search may find a photo you can use to verify you have the right person. If looking for female classmates, search engine results may provide a lead on a married name that could then be used when searching social media networks.
Use alumni searching networks. Some are free, but the best networks charge a small fee. Don't sign up for any "subscription" services because you'll only use the service once. Alumni search networks are best for finding people who have married and changed their names, as they will conduct search by maiden name. The networks check all public records, but likely will only turn up mailing addresses and land line phone numbers.
Use the school itself as a last resort. It could have the contact information you're looking for. Old friends might have children of their own at the school, or if they had kids in the school but moved, they might have left a forwarding address and contact information. Contact the school's alumni organization if it has one. Take note, though, that, due to privacy rules and laws, the school may not be willing to share any personal information to anyone not related to the person in question.
If you graduated from the same high school, try the high school social network.