of running my own web server in my office - I've worked with too many servers in corporate offices to want the hassle of worrying about up time, particularly at weekends and during holiday periods.
Like Taran, I run a dedicated server with a hosting company. The server's in a secure facility in London's docklands area, and is monitored on a 24/7 basis; if it goes down it's rebooted immediately, and I don't have to worry about it.
There are just too many problems associated with running a home server for it to be viable, unless it's purely for your own amusement. If it was worth doing I assure you we would all be doing it.