With the TomTom BRIDGE connected to a development PC, you can take screenshots directly to the PC by using eclipse DDMS camera functionality. In eclipse go the the DDMS view, select the TomTom BRIDGE device and click the camera icon.
Alternatively you can take a screenshot via adb using "screencap -p >/sdcard/screenshot.png".
To take screenshots without a PC attached long press the power button and select "Take a screenshot". The screenshots are stored at the following location: /sdcard/Pictures/Screenshots.