HTTrack – Web Site copier is a free, Open Source, cross-platform(Linux, Mac and Windows) offline browser utility that permits you to download an entire website to local folder on your computer. This way you can go through the website while offline or not connected. After downloading the website; including images, it reconstructs internal links for better offline browsing.
Secondly it also create a mirror website of the downloaded website. When I used it to download Kabatology on a local folder, it created a mirror website for kabatology =>http://martin-laptop:8081/website/www.kabatology.com/index.html and download all images including all gravatars used on Kabatology.
So, if you find yourself in situation where you have to present a website to a client but that does not have an internet connection, then think of HTTrack.
With HTTrack you can also comfortably read e-books whilst offline.
The internal organization of folders is really excellent as it separates each group of downloaded objects into different folders with the name of the proprietor. This makes it easy to scrutinize all what has been uploaded to your blog or site in one way or the other.
Being cross-platform, there are packages for Windows(95/98/NT/2K/XP), Mac OSX , LInux(deb, rpm, Python). In Ubuntu it can be installed from the repository with a simple
sudo apt-get install httrack
via [HTTrack – website copier]