I've been using httrack for a long period of time. It's very useful when I'm
out going somewhere and I want to view pages for offline use. I am a web
designer and sometimes I also need to download my clients pages for
redesigning. 

There's this software called website ripper copier that serves the same
purpose as httrack but is sold. It has lots of BS when all it can actually do
is download the same files and do the same things that httrack can do. 

thanks httrack. :)