VirtualBox has a USB pass-through function and according to their forums it is possible to connect a webcam with the 4.3 version which is available on OMV. Sadly even though the webcams show up in the device manager of XP and Win7, they don't show as available in any software. Suggestions on their forums when running VirtualBox on their forums are to select "device" from the menu and choose the webcame. This menu is not available when viewing the OS in console using OMV. Another suggestion is to launch Virtualbox as root, though that usually is not recommended and I don't even know how to launch is as root since OMV does it all automatically. Do note all webcams are available under the USB settings for the Guest machine.
Anyone successuflly got webcams working in Virtualbox under OMV?