17 Again marks Zac Efron's second number one opening in six months. The Russell Crowe thriller State of Play took a respectable second place with Crank: High Voltage taking sixth place with only $6.9 million. Here's the top five:

1. 17 Again: $23.7 million
2. State of Play: $14 million
3. Hannah Montana The Movie: $13.4 million
4. Monsters Vs. Aliens: $13.2 million
5. Fast and Furious: $11.7 million

Four new releases this week:

What's It All About:
A 99 minute tour of life on Earth edited down from a 12-hour TV mini-series. This one releases today to commemorate Earth Day.
Why It Might Do Well: Dude, check out the baby polar bears! Also Rottentomatoes.com is giving it an 83% Fresh rating.
Why It Might Not Do Well:
It's a smaller release and much of the footage has already played on TV
Number of Theaters:
$8 million.

What's It All About:
A morose-looking small town boy comes to the big city and finds he has a talent for competitive bare-knuckle brawling.
Why It Might Do Well: I suppose anything is possible.
Why It Might Not Do Well:
The overly complicated title may confuse some.
Number of Theaters: 2,100
$7 million