I picked up an Aiptek Pencam Trio at my local Walmart.com (Every Day Low Wages!). Stay away from these—while gphoto supports some versions of them with the stv680 driver, the ones in stock at Walmart these days don't seem to be supported. I believe the chipset in these cameras has changed, along with the USB id's for vendor and product.
You can tell if you have an incompatible by looking at the id's reported by the kernel when you plug in the camera. If the output of dmesg looks like
hub.c: new USB device 00:1d.1-2, assigned address 3usb.c: USB device 3 (vend/prod 0x8ca/0x111) is not claimed by any active driver.Even if you force these id's to be recognized as a Pencam Trio, you'll end up with an unspecified error in libgphoto2's I/O routines. Here is the relevant entry in /proc/bus/usb/devices.
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hubE: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=255msT: Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 4 Spd=12 MxCh= 0D: Ver= 1.10 Cls=ff(vend.) Sub=ff Prot=ff MxPS= 8 #Cfgs= 1P: Vendor=08ca ProdID=0111 Rev= 1.00S: Product=Dual-Mode Digital CameraC:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mAIf anyone finds out how to get this working under Linux, I'd like to hear about it.