As you might expect from the title, Silent Hill Origins deals with the origins of Silent Hill.
The game follows truck driver Travis Grady, "who gets stuck in [Silent Hill] while making a routine delivery. He quickly discovers the locals aren't quite normal, and neither is the town. To complicate matters, Grady is confronted by crippling memories from his troubled past. He must escape from Silent Hill while resolving the memories that have plagued him since childhood."
Continuing the series' trend, there are plenty of creepy looking children with soulless eyes - a couple of which you can see in a trailer after the jump.

The PS2 port was rather dark, especially when Travis was inside the hospital. I never played it on the PSP. I'm just going by what I saw for myself.