Notary Public ?

According to Wikipedia a notary public is... "a public officer constituted by law to serve the public in non-contentious matters usually concerned with estates, deeds, powers-of-attorney, and foreign and international business. A notary's main functions are to administer oaths and affirmations, take affidavits and statutory declarations, witness and authenticate the execution of certain classes of documents, take acknowledgments of deeds and other conveyances, protest notes and bills of exchange, provide notice of foreign drafts, prepare marine or ship's protests in cases of damage, provides exemplification and notarial copies, and perform certain other official acts depending on the jurisdiction. Any such act is known as a notarization. The term notary public only refers to common-law notaries and should not be confused with civil-law notaries."

I know lot of people that do this on the side in addition to their regualr jobs just to supplement  income. Depending on what you may need to have notarized, one may get anywhere from $25-150. 

Many noataries now offer. "I will travel" offers...meaning they will come to your home or your office to notarize documents.

If interested, read more about it and check your local jurisdiction in regard to the credentials needed in your town.