Hello,
 This device:

 http://www.dealextreme.com/details.dx/sku.12057

 it has a BenQ M32 GSM/GPRS modem sitting behind a PL2303

 BenQ datasheet fwiw: http://www.sure-electronics.net/rf,audio/GP-GC006-pdf.pdf

furball.peoples$ usbdevs -v                                                    
Controller /dev/usb0:
addr 1: high speed, self powered, config 1, EHCI root hub(0x0000), Intel(0x8086), rev 1.00
 port 1 addr 2: high speed, self powered, config 1, Hub(0x2504), Standard Microsystems(0x0424), rev 0.01
  port 1 powered
  port 2 addr 3: low speed, power 100 mA, config 1, Dell Premium USB Optical Mouse(0x3016), Dell(0x413c), rev 29.00
  port 3 powered
  port 4 addr 7: full speed, power 500 mA, config 1, PL2303 BenQ GPRS Modem(0x0609), Prolific Technology(0x067b), rev 0.00
...clipped...



 Here are patches to usbdevs and uplcom.c to get it to attach.

Index: uplcom.c
===================================================================
RCS file: /cvs/src/sys/dev/usb/uplcom.c,v
retrieving revision 1.53
diff -u uplcom.c
--- uplcom.c    24 Sep 2010 08:33:59 -0000      1.53
+++ uplcom.c    16 Nov 2010 21:31:01 -0000
@@ -164,6 +164,7 @@
        { USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2303X },
        { USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2303X2 },
        { USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_RSAQ2 },
+       { USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_BENQPL2303 },
        { USB_VENDOR_PROLIFIC2, USB_PRODUCT_PROLIFIC2_PL2303 },
        { USB_VENDOR_RADIOSHACK, USB_PRODUCT_RADIOSHACK_PL2303 },
        { USB_VENDOR_RATOC, USB_PRODUCT_RATOC_REXUSB60 },
@@ -182,7 +183,7 @@
        { USB_VENDOR_TDK, USB_PRODUCT_TDK_UPA9664 },
        { USB_VENDOR_TRIPPLITE, USB_PRODUCT_TRIPPLITE_U209 },
        { USB_VENDOR_SMART, USB_PRODUCT_SMART_PL2303 },
-       { USB_VENDOR_YCCABLE, USB_PRODUCT_YCCABLE_PL2303 }
+       { USB_VENDOR_YCCABLE, USB_PRODUCT_YCCABLE_PL2303 },
 };
 #define uplcom_lookup(v, p) usb_lookup(uplcom_devs, v, p)
 
Index: usbdevs
===================================================================
RCS file: /cvs/src/sys/dev/usb/usbdevs,v
retrieving revision 1.524
diff -u usbdevs
--- usbdevs     16 Nov 2010 19:25:27 -0000      1.524
+++ usbdevs     16 Nov 2010 21:31:01 -0000
@@ -3019,6 +3019,7 @@
 product PROLIFIC PL2301                0x0000  PL2301 Host-Host
 product PROLIFIC PL2302                0x0001  PL2302 Host-Host
 product PROLIFIC RSAQ2         0x04bb  PL2303 Serial
+product PROLIFIC BENQPL2303    0x0609  PL2303 BenQ GPRS Modem
 product PROLIFIC PL2303                0x2303  PL2303 Serial
 product PROLIFIC PL2305                0x2305  Parallel printer
 product PROLIFIC ATAPI4                0x2307  ATAPI-4 Bridge Controller

 I don't have a SIM card to test it fully atm, but:

furball.peoples$ sudo cu -l /dev/cuaU0 -s 9600                                 
Connected
T
OK
AT+CREG?
+CREG: 0, 3

OK
AT+CSQ
+CSQ: 99,0

OK
~
[EOT]
furball.peoples$

(AT+CREG? returns 0|1 if it's registered with the network, and with no SIM card, 0 is expected)

 My anoncvs mirror didn't have the latest commit from damien@ about 2 hours ago fwiw

Thanks,
 marco