im not too sure, with li-ons, they have a "smart circuit" inside that says when they are charged.
wiring them in parallel may screw up this circuit and make them over/undercharge.
Thats is with pre-built battery devices like in cell phones and such. Since he is using individual cells, they do not have any protection circuitry built in.
You don't need any switches or anything, just solder wires from each cell in to a connector, this forms a balance tap. This way you can charge each cell individually.
See this picture here:
The red connector is the "standard" connector for powering devices. The battery is the 3 cell lipo, so out of that standard connecter you get the 11.1v nominal out. However, to charge it, the white connector is used. The white connector has connections for each of the individual cells, so that each cell is charged to their max potential.
I would greatly avoid using your camera's battery charger, if the cameras battery has built in circuitry, the charger will not be able to charge your batteries properly. You can buy chargers for your batteries for cheap on dealextreme, just look for flashlight battery chargers (since the li-ions you are using are usually meant for flashlights)