Here's an idea for anyone with a modicum of influence over at Vodafone HQ.
I have tablet share. My "tablet" is in fact a wifi hotspot thingie, no phone or txt functions. It only does data. We use it with our tablets if we find ourselves out of free wifi when overseas without draining the life out of my phone.
I know from experience that if I use my phone and my hotspot it will cost me $10 a day.
Maybe data-only SIM's could be a little bit cheaper than full monty SIMS?
So there it is, just a thought.