Thanks Wm.Mays for the extensive info! I'll be in New York and NV/CA in August/September and will bring my Mini 9. Would be great if there was some acceptable prepaid dataplan available.
I know that people over here (in the Netherlands that is) are using Vodafone Ireland prepaid simcards on their vacations. These cards can be bought on Ebay and mobile internet comes at € 0.99 for 50MB used during one day. Sounds like a fair deal if it's usable in the US.
This is the Vodafone-page:
Mobile Internet FAQ from Ireland's Leading Broadband & Mobile Phones Provider,Vodafone