Try opening a console *before* you plug the camera in, then run
<code>
less +F /var/log/messages
</code>
Now plug in the camera, already switched on.

(You might need to be root; syslogd needs to be running for this to work)

Hopefully you'll see some activity in the console window:
Mar 14 09:46:00 tunix kernel: scsi0 : SCSI emulation for USB Mass Storage devices
Mar 14 09:46:00 tunix kernel: usb-storage: device found at 3
Mar 14 09:46:00 tunix kernel: usb-storage: waiting for device to settle before scanning
Mar 14 09:46:00 tunix kernel: usbcore: registered new driver usb-storage
Mar 14 09:46:00 tunix kernel: USB Mass Storage support registered.
Mar 14 09:46:05 tunix kernel: Vendor: USB Model: Flash Disk Rev: 2040
...
Mar 14 09:46:05 tunix kernel: sda: sda1
Mar 14 09:46:05 tunix kernel: sd 0:0:0:0: Attached scsi removable disk sda
Mar 14 09:46:05 tunix kernel: sd 0:0:0:0: Attached scsi generic sg0 type 0
Mar 14 09:46:05 tunix kernel: usb-storage: device scan complete

In this case the device to mount is "/dev/sda1" (like suggested by sakiZ); since
sda1 didn't work for you, hopefully something else shows up.