If it has a flash on it, then it can become a makeshift flashlight. Android has dozens of apps that activate the devices flash and keeps it on to light up the way. The only problem is that the vast majority are not compatible with the Galaxy Tab.
The one I found that worked with the Tab is called Tiny Flashlight + LED. Its free download from the Android Market includes both an application and a widget and is ad supported.
When you first open the application it will show a dark metal background with a power button. If you press the power button, the LED will turn on in roughly two seconds. Tapping the circle in the top right corner brings you to other flashlight options. Some are practical like the screen flashlight that makes your screen bright white, but some have no practical purpose like the warning lights. I can just imagine a road worker carrying his Galaxy Tab out to work at night using this app. Hilarious.
The widget on the other hand only has one mode, LED Flashlight. This is perfect for when you need a light quickly. Just put one of the seven different widgets on one of your homescreens, tap it and you will be blessed with light in about two seconds.
Now this is just the one option that I have found, and there very well could be others out there. Please let me know in the comments if you have found any other/better options.