LightZone from Lightcrafts comes to mind. It's not really the same, but will do some similar functions. You also don't need to have another program (like Photoshop) to use it. I used it mainly for darker shots or ones where I need to make different adjustments to regions of a photo.
The biggest problem with LightZone is that it is written in Java, which means it's a slow memory hog. Make sure you have at least 1 GB of RAM and aren't running anything else that's system intensive. That said, I've gotten some impressive edits from photos I thought where lost using this program.