It's possible this is the TenX model refered to (who knows, I'm guessing!)

http://www.ebay.co.uk/itm/USB-Thermometer-Temperature-Data-Record-for-PC-Laptop-/110709519689?pt=UK_Computing_Other_Computing_Networking&hash=item19c6cd3549

OK I've bought one, I'll post up if it works, keep in mind stuff takes 2-3 weeks to arrive from HK.

Lorian wrote: It says on the bottom of the setup screen.

I couldn't see that anywhere, although I'm running 1.5.2b (as reported by the router, downloaded from Draytek's UK site)
I've only just got the router running again, having moved house and gone through a BT order mess-up which then delayed getting FTTC re-installed!

Its now located in a hallway rather than in a cupboard amongst other kit so knowing the temperature is a bit less necessary although the USB temperature facility remains intriguing.

It will be interesting to see whether the sensor you've ordered works

Cheers,
Ashley