I have connected a USB device that creates a USB VCP profile to my Motorola Xoom in order to enable my Xoom apps to interface with RS232 devices.
My small test program shows the following details for the USB device:

Model: /dev/bus/usb/002/002
Id: 2002
Class: 0
SubClass: 0
Protocol: 0
VendorId: 1659
ProductId: 8963
Number of Interfaces: 1
>> Interface 0 -> 3 Endpoints

With all the information we can tell the device to open a custom application when the USB device is attached. To do so, the following information should be added to the ‘activity’ tag in the Manifest.

<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
</intent-filter>
<meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/usb_device_filter" />

The XML file is a resource file that contains information about the USB Device, that should be placed in /res/xml

<resources>
<usb-device vendor-id="1659" product-id="8963" class="0" subclass="0"
 protocol="0"/>
</resources>

When the activity starts, it can retrieve the USB Device information by calling:

device = (UsbDevice)getIntent().getParcelableExtra(UsbManager.EXTRA_DEVICE);

If the device is not null, then you can open an UsbInterface and get the UsbEndpoint in order to read and write information.