It appears that due to a fault in the Leopard upgrade from Tiger, it misses copying some Apache 2 config files across which means that if you want to use Web Sharing, you’ll just get 403 access denied errors when viewing http://<your local ip address>/<short user name>/. It is, however, possible to fix it with a bit of tinkering.
First up I needed to tweak Finder so that it could see hidden files and folders, so via Terminal I entered the following:
defaults write com.apple.finder AppleShowAllFiles TRUE
To revert it back later I entered:
defaults write com.apple.finder AppleShowAllFiles FALSE
After that tweak I was able to browse to /etc/httpd/users/ and copy all my *.conf files to /etc/apache2/extra/. I was asked for my administrator password after which I went to System Preferences / Sharing and turned Web Sharing Off then On to restart it. And with that I was able to access my local website again.
If however that hadn’t worked, I could have created a <short user name>.conf file in my /etc/apache2/extra/ folder with the following text in:
<Directory “/Users/short user name/Sites/”>
Options Indexes MultiViews
Allow from all