Volunteers make the genealogy world go 'round. Chances are you've gained from a charitable family history undertaking — perhaps an online obituary project, journal-article index or passenger-list transcription. Now it's time to give back. National Make a Difference Day <www.usaweekend.com/diffday> is Oct. 23, so use the occasion — and the following ideas — for inspiration.

Do-gooders such as Molly Bell of Minden, La., are indispensable to long-distance genealogists. Through the Random Acts of Genealogical Kindness <www.raogk.org> Web site, Bell looks up public records, photographs tombstones and does other simple favors for faraway researchers with ancestors from her area. “I know how people feel to be stuck where they are, without any knowledge of the places their ancestors lived,” says Bell, who does at least one genealogical kindness per month. “I'm a sucker when it comes to giving someone a new connection with their past — it's so fulfilling.” The Web site Books We Own <www.rootsweb.com/????bwo> works on a similar principle: It connects researchers seeking information from hard-to-get books with the books' owners, who do lookups and e-mail their findings.