Here is what dreamhost panel does

By default, something like:

http://www.domain.com/pics/

would point to:

/home/user/domain.com/pics/

From here you can remap that URL anywhere you'd like. It's great for organizing a website among multiple users!
For Example:
If I wanted to create a new ftp account virtual host called 'subaccount' that would be able to place things in folder '~folder' and have it be visible on domain.com/~folder/ and only there.
remap /home/subaccount/domain.com/~folder/ to http://www.domain.com/~folder/

Also, please check out my last help thread on how to get the contents of ~folder/ to show the contents of a sub-domain on a different server.

for instance folder.domain1.com hosted at hostingcompany1 would show up in domain2.com/~folder/ at hostingcompany2