You may want to check out Adobe's Flash Media server http://www.adobe.com/products/flashmediaserver/ OR Red5 http://osflash.org/red5. They both provide video and audio streaming through RTMP (Real Time Messaging Protocol). You can search for web hosting servers that already have Red5 installed. Red5 will be much cheaper than Flash Media Server, since it's open source. The video or audio files don't get cached onto the users system and it allows you to jump at any point in time of the playing content.