I'm receiving a lot of correspondence on how to broadcast live events on the web.
I did my first live event back in the mid 90s and, surprisingly, things haven't changed that much.
Watching the Olympics on the BBC reminds me of sand filled days on remote beaches off the African coast attempting to get live pictures from the PWA World Windsurfing Tour out live over the internet.
However you handle a live webcast the components are the same:
Pictures - you will need on or more cameras; the better the quality, the better the output, so HD is always preferable even for webcasting. Lightweight is the way to go to save on excess duty on airplanes if you're going abroad, or hire locally (unless, of course, you're filming windsurfing in 30 knot winds - then heavyweight equipment becomes a plus!). If you're using multiple cameras I'd always suggest a pro dedicated mixing desk such as Sony's Anycast. Cables are a pain, and the emerging wireless solutions are worth looking at if the budget allows.
Presenter - watching the red button coverage of the Olympics with the commentary appearing and disappearing is disconcerting - having someone to interpret the pictures and ask questions is a long held TV tradition; in an ideal world if you're running commentary having two people improves the banter. The problem with this is that you then need monitors for them to watch the video output and special mics for noisy situations. Alternatively you can cheat by having them watch and commentate from a studio - or even your office.
Connectivity - ah, the biggest issue of all is making sure that you're able to get pictures from the location.. ah, I could tell you some stories about how we managed to get pictures live.... The best, but most expensive way, is to send a broadcast signal, but this involves getting a satellite dish and technician on location, booking a satellite, having a downlink with an encoder, etc.. (There are service providers who can do all of this for you). An alternative, which I always favour if possible, is to encode on site. You will need a reliable upstream link of 1Mbps for this and an encoder with a dedicated encoding card such as those from Viewcast. I've used everything from microwaves to hacked together lengths of CAT5 to get an image from the mixing desk to the encoder and to a point where there's sensible bandwidth - and always make sure that you have Plan B for when some muppet decides to service the local telephone exchange just as you're about to go live.
Network - a typical Internet TV service only makes modest calls on a network - a single server can easily cope with 200 simultaneous connections, and with each person watching 15 mins, this would equate to (200 x 4 x 24) nearly 20,000 viewers a day; but if all of those viewers arrive at the same time you'll need 100 servers; that's when content delivery networks (CDNs) come into play. On top of this, you will need someone managing and optimising the network, providing support in the same way that TV playout facilities do.
Technicians - more than anything you'll need a bunch of talented, committed people who are resourceful and adaptable; remember, if anything can go wrong, it will go wrong and the first major lesson I learnt in TV was that there are no excuses.