What iOS apps will take pictures and not send them to Photo Stream by default? I'm looking for a way to take pictures without them going into the Photo Stream. Rather than have to remember to toggle it on and off as I adore it for my personal pictures, I'm looking for an app that lets me control this.

I don't really care if it stores the photos in it's own storage space or somehow can toggle a "do not send" status before it gets added to the normal camera roll.

Has such software been released for iOS?

I will still want this if Apple releases a way to delete select photos from the stream. I am in the habit of documenting work sites using my phone's camera that I really won't ever want to see in my personal photo stream. I'd rather pay for another app than have to remember to enable/disable the stream in the Settings App before and after a work photo session.
Since Photo Stream backs your Camera Roll, any app that uses its own storage space rather than the Roll should do - and I doubt many have been (or can be) updated to backup their own storage to Photo Stream at this early stage.

I'm a fan of Camera+, myself. It saves photos to its own storage, and lets you push them to the Camera Roll (and, therefore, Photo Stream) if and when you want to.