Helio will shut down its Hybrid EV-DO / Wi-Fi service starting May 8th. Users of the service will still be able to access the Boingo Hotspots and 3G data service through May 7th, but afterwards, the cards will no longer work. Hybrid blended Wi-Fi and EV-DO radio technologies and used software to control which radio was connected to the Internet, automatically switching to the cheapest connection. Helio put a notice on its site saying that users are welcome to keep their cards, and that all accounts will be billed a prorated amount up until May 7th. If accounts were already charged for service past May 7th, a refund will be issued.