Rent Exchange for $14 per/user/month

found on GeekNews and i'm guessing it's .Net-based …

"Broadband customers of Telewest can now subscribe to a "rentware" version of Microsoft Exchange with Outlook using their cable modem PC connection. The U.K. service costs 10 pounds ($14) a month on top of their existing cable modem subscription."

another interesting quote:
"Obviously there plans to extend the service to Microsoft Office, but we're also looking at the possibility of offering access to financial software for small businesses across the broadband connection…"

From: U.K.: Broadband 'Rentware' – MS-Exchange For 10£ Month