You can do it. Simply by copying or by using 'dd' program. dd allows (among other things) to build disks/partitions/floppy images. Syntax looks this way
dd if=/dev/hda of=myimage.img
It creates an image of /dev/hda1 (first partition on your first disk) to myimage.img file. Then you can compress it and send/move to another machine. When writing it back switch 'if' and 'of' parameters (of course, use the right partition and the right file name). Running 'man dd' will show you many more possible options.
The partitioning program you can use from most installation cds (in rescue mode but also using standard installation mode) is ...fdisk
It's text mode, so may b hard first time you try it. Has descriptions of all the options so if you read them carefully before using it shouldn't be that hard. You may also other tools available like parted (used to change partition sizes etc).