Yes and no. There exists infastructure in the Internet designed to acheive what you are looking to accomplish. The problem is that these require certain IP addresses, routing requirements, etc...
For all practical purposes, you can't acheive your intentions for free.
You may wish to review these articles:
http://www.teamsolutions.co.uk/streaming.html
http://www.oreilly.com/catalog/sound/chapter/ch05.html
I haven't had to do this, but you could either Google around for "Streaming Hosting" or "Content Delivery" ... but you'll probably be best off with Live365.com (if they have a live streaming option.)
Alternatively, you can call your ISP and ask if you can pay ala carte a few more bucks a month and up your upload speeds.
Remember, if you go with a company that will host your streaming (IE, their servers log into your home machine and "rebroadcasts" the stream) - you'll want to differentiate the companies that offer streaming off of playlists or files and actual "live streaming". Some may refer to "live streaming" when it's actually just a plain static stream.