If you're looking for a quick, easy way to duplicate a MySQL Row, try the following example:
INSERT INTO Tbl1 (Col2, Col3, ...) SELECT (Col2, Col3, ...) FROM Tbl1 WHERE Col1 = 1;
This example assumes you want to duplicate the row where Col1 equals 1. You could change the where clause to anything for that matter. However, if there are more than one rows selected from the SELECT statement, it will INSERT each row, not just one.
Likewise, you could duplicate a whole MySQL table using the following:
INSERT INTO Tbl2 (Col2, Col3, ...) SELECT (Col2, Col3, ...) FROM Tbl1;