This works:
127.0.0.1 www.somesite.com
But not this:
127.0.0.1/somepath/www www.mysite.com
What am I doing wrong? Is it possible to map a full path like this? If not, what is the easiest way to accomplish what I want to do here?
The simple answer is that you can't use the hosts file to redirect to specific URLs. It can only be used to map hostnames to IP addresses.