Suitability varies with camera facilities and with quality of the charger, but in many cases you will have no problems doing this. Usually a special adaptor will be needed but, in this case, it is probably a matter of "plug in and go".

The EX-1 camera has an unusual feature - it will accept charging input from a 5 Volt "USB" power source and charge the battery while the battery is in the camera.

This site says:

• Alongside the HDMI connection is a proprietary connector for Samsung's power and sync cable - the EX1 is recharged with the battery in-camera, either from an electrical socket or or alternatively straight from a USB port connected to your computer, rather than via an external recharger

So, for this camera, there should be a cable supplied that will allow the camera to plug into the USB power pack and recharge the battery while it is inside the camera. Most cameras that connect to a USB port use it only for data transfer and not for powering and charging.

For cameras that do not have this charge-in-camera capability you would need a "5V USB power supply" to battery charger. After market chargers that achieve this are available in various forms, but manufacturers so far do not tend to do this.
[For single cell LiIon batteries the minimum required circuitry is extremely simple and cheap. For batteries with 2 LiIon cells in series (typically DSLR's and larger cameras) a somewhat more complex power supply is needed.]

Power supply quality: Most "USB" chargers provide voltages within an acceptable range. However, I have seen a few "USB power supplies that do not limit the supplied voltage to the correct range, and I have seen some USB charging ICs that would be damaged by such supplies. If you wish to be 100% sure (or maybe 99.31412%) then have a competent person check the output voltage of the power supply in unloaded and loaded condition.