GNU wget can create a very usable local or offline mirror of an entire folder of a website using the following combination of options.
From the output directory, use this invocation:
URL=http://www.emsl.pnl.gov/docs/global/index.shtml wget -r -l inf -k -N -np -p -E $URL  | 
You can play around with the options:
- -r
 - recursive
 - -l inf
 - follow link infinitely
 - -k
 - convert links after downloading
 - -N
 - time-stamping
 - -np
 - no parent
 - -p
 - retrieve prerequisites of pages
 - -E
 - page extensions according to MIME type
 
The files will be stored under hostname/path/to/file. If you know up front that the origin of the files is restricted to a particular host or even subpath, you can additionally use:
- -nH
 - no subdir for host
 - –cut-dirs=N
 - strip N path components
 
Alternative when you want to download a flat Apache directory listing:
wget -r -np -l1 -nd -N $URLThe option
-ndprevents the creation of the local directory structure.Afterwards you can probably remove
index.htmlandrobots.txt