Don't wait for Vodafone
Vodafone havent got a clue.
The vodafone k3760 stick is actually an Icon 411 made by Option (it just has a vodafone sticker on it) so it's really Option's fault there are no drivers.
But wait.. whats this...
http://www.option.com/en/support/software-download/usb-modems/icon431/
Yes, thats right, Option have already updated their drivers for snow leopard. Just download and install this and your stick will work perfectly.
Of course, vodafone wont tell you this because these drivers dont include the piss-poor vodafone branded pointless VMC application that serves no purpose. They'd prefer you to wait 2 months until Dave their IT guy can do get round to copying the driver into their bloated installer and doing a bit of search/replace on the text.
If it isn't set up already, you will need to configure the G141x Modem device that comes up in the Network preferences panel. On the advanced tab set it to be an Option Nv GSM modem. Set the APN, phone number, account, password from the vodafone details on this page:
http://www.filesaveas.com/gprs.html
Biting the hand that feeds IT
