So, the delightful Kathy bought me a Marks & Spencer USB Missile Launcher (unfortunately out of stock at present or I'd have linked directly to it. Try searching on eBay / Google to see what I mean.) Problem. WinXP/2k only drivers. That's no fun.

Plugged it in to my laptop (as you do). dmesg reports: 

input: Tenx Nonstandard Devic as /class/input/input6
input: USB HID v1.10 Device [Tenx Nonstandard Devic] on usb-0000:00:1d.1-2
input: Tenx Nonstandard Devic as /class/input/input7
input: USB HID v1.10 Device [Tenx Nonstandard Devic] on usb-0000:00:1d.1-2

lsusb says: 

Bus 002 Device 004: ID 1130:0202 Tenx Technology, Inc. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0         8
  idVendor           0x1130 Tenx Technology, Inc.
  idProduct          0x0202 
  bcdDevice            1.00
  iManufacturer           0 
  iProduct                2 
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           59
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Devices
      bInterfaceSubClass      0 No Subclass
      bInterfaceProtocol      0 None
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.10
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      43
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               1
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Devices
      bInterfaceSubClass      0 No Subclass
      bInterfaceProtocol      0 None
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.10
          bCountryCode           33 US
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      23
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               1

The Windows software appears to consist of TenxHID.dll (24k) and Missile_Launcher.exe (908k). TenxHID only exports DeviceIni, ReadBuffer and WriteBuffer AFAICT. Which implies the higher level stuff is done in the exe to me. I think it's a job for USBSnoop and a Windows box, but that'll have to wait for a few days until I get back to a WinXP box I can use to fiddle. Unless someone else manages to write a driver in the meantime. :)