I’ve not heard of any online 911 type service, so I’m not sure how one would receive a quick response from an online source. My first thought would be to send IM’s and/or e-mails to all of my contacts asking them to get in touch with emergency services for me. Beyond that, I guess one could use a search engine to find websites for local police or fire departments and use any of the “contact us” links to e-mail for assistance. Since most of those addresses are for administrative personnel and not intended for emergency use, I would suspect that one would risk either a very slow response or none at all. The e-mails might be blown off as a hoax.