If you're worried about the speed at which your target audience connects to the Internet (with regard to rich, streaming and other bulky media), here's some good news. The number of high-speed Internet hookups in the US rose 57% in the first six months of this year and the rural subscriber rate is rising fast. According to the Federal Communications Commission, by June 30, about 4.3 million homes and small businesses subscribed to high-speed Internet service, up from 2.8 million at the end of 1999. High-speed service was available in all 50 states, the District of Columbia and Puerto …