How far it's from Linux?
When i plug it into USB port dmesg shows:

drivers/usb/input/hid-core.c: ctrl urb status -32 received
input: USB HID v1.00 Device [PDT VoIPvoice USB Phone] on usb-0000:00:1d.0-2

We'll have to wait for the devs to add a configuration option to select which device Skype should use (as of now, you can only use /dev/dsp "out of the box"). You may be able to get it to work with a bit of module-shuffling or the dsp hijacker posted elsewhere in this thread. Even then, I doubt it will support DTMF or any other features from the Cyberphone except being able to use it as an audio device.

Not quite sure though - haven't got one myself so it may work