so... happened to me right now several times... wanted to take pictures for the poll because of the chrome ring around the cam reflects the light and is responsible for a hazy look of the right top of the picture...

here's how i make my cam app crash:
1. start the cam app
2. take one photo and wait till the preview is gone
3. take another photo and wait again till it's gone
4. click the "view images" button at the right bottom
5. click on one of the two pics you made
6. when it's zoomed in click in the middle of the pic to pop up the menu at the bottom
7. delete the pic with the trash-icon and "yes"
8. the other pic will show up
9. delete it the same way you did with the other picture
10. go back with the arrow top right
11. close the image view with the cross top right
12. click in the dashboard on the preview of the cam-app which is in standby
13. when it's fullscreen again try to take a photo
14. it crashes!? o.O
15. now you can open the cam app but you can't take pictures/videos anymore - it crashes immediately

edit: reboot helps to get it work again. plausible.
BUT: connecting usb, entering mass storage mode and disconnecting usb get it working too?!?!?!