That's about $1.70 U.S.
"Pay for the first 0.5MB… and we’ll give you the next 14.5MB for free."
Then Vodafone says:
"There’s no catch. The first 0.5MB (approximately 20 pages) you use on any given day will cost you up to 85p. The next 14.5MB won’t cost you a penny."
"No catch,", eh?
Scrolling down the page, we read:
"The 85p per day charge and monthly data subscription cannot be used for Voice over Internet Protocol (VoIP) services such as Skype or Peer-to-Peer services (such as instant messenger services, text messaging clients or file sharing). These services will not count towards the 85p per day charge or monthly bundle, and are charged separately at £1.70 per MB (about $3.40 U.S.) with a 4p (about $8 per day)minimum charge for each data session."
Watch out. North American carriers will be looking at this plan, to see if it succeeds. Then, get ready for Skype surcharges over mobile.