Synchronize creation of rows between tables
Let's say you have this:

CREATE TABLE posts
(
    id int not null auto_increment,
    title varchar(100),
    primary key (id)
) ENGINE=InnoDB;
CREATE TABLE posts_content
(
    post_id int not null,
    blobdata blob,
    primary key (post_id),
    CONSTRAINT `FK_posts` FOREIGN KEY (`post_id`) REFERENCES posts (`id`)
) ENGINE=InnoDB;


You could perhaps run the two INSERTs like this:

START TRANSACTION;
INSERT INTO posts (title) VALUES ('some-title');
SET @GivenPostID = LAST_INSERT_ID();
INSERT INTO posts_content (post_id,blobdata)
VALUES (@GivenPostID,'oxbdsixds');
COMMIT;


Give it a Try !!!