But fear not my friends... there is a graphical front-end written for the original Unix command called "dd". It's an advanced piece of tool given by aliens :P that has the ability to copy/move both raw and ASCI (character encoded, okay now I got you more confused) data in Linux/Unix systems.
Let me give you an example.
Let's say that you have 700MB of CD filled with ".png" images (millions of them). Then copying them can take a bit of a time. Because in the more conventional method of copying those files has to be done within a certain "protocol". So the OS has to read each file individually (including its size, tags, etc) and paste them, etc.
But you can do the same task by creating a CD image which can be done within an impressively shorter time period, which is somewhat similar to Raw data (in a way). So what the heck is the difference then?. Well while dealing with files as ASCI ... we can edit/copy/paste individual files (we can copy certain pictures only, etc). But with Raw copy... the application does not care about individuality.. it just read all the 1s and the 0s (that's all there is in our dumb computers) and paste them, basically it deals with them as a "whole".
Then we can use some sort of an application such as image viewer to read that image/raw data and use its ability to read and take apart those Raw data and "extract" those individual files.
Anyhow,back to the topic. If you want to make an entire HDD or individual partition backups ("image" files) in GNU/Linux easily ... then you should try the GTK written "dd" command front-end called Gdiskdump. Since there is a GUI, now you can easily save/restore the saved data using Gdiskdump as well.
If you use Ubuntu 11.04 Natty Narwhal, then please download the .deb file from here and once the download is completed, just double click on it and it should be installed.
Later you can run it by: "Applications" -> "Accessories" -> gDiskdump or in Natty, search for "gDiskDump" in Dash.