I have just managed to "convince" my Vodafone Smartmodem (a 3G/HSDPA wireless modem on Vodafone Romania) to talk to the iLiad via USB serial (the usbserial module - see the other thread in this section of the forum). The modem appears to work fine (I can connect to it, send it AT commands, etc). I've also compiled the PPPD package and the kernel PPP modules, tomorrow I will try to make it connect via PPP. If that works, I'll publish the entire procedure and the necessary modules here.
As a teaser, I'm attaching a photo of the iLiad hooked up to the Vodafone modem. Looks like an alien contraption but it works