Today on "World News with Charles Gibson":

Primary Day:
The Democratic presidential hopefuls face off once again over the 103 delegates at stake in today's two primaries. Sen. Hillary Clinton is expected to take Kentucky, while Sen. Barack Obama is likely to grab a majority of pledged delegates in Oregon. ABC's political team will bring you the latest as the votes come in.

Protecting Your Young Drivers:
Could there be a way to protect your teen from their own risky driving? ABC's Lisa Stark reports on a cutting-edge technology that gives you a real time view of what your child is doing on the road.

And on our "World News" webcast along with our top headlines:":

D.J. Scientific:
The "World News" webcast sits down with Mark Branch, who is a NASA aerospace engineer by day and one of Washington's most popular DJs by night.