if you got some kind of linux distro installed, just go (in terminal) to the dir where the image file is located, and type "file filename.img" if it returns something like ext2 filesystem, simply do:
mount -o loop filename.img /mnt
and the file will be mounted on /mnt, so you can access it using cd /mnt
if it returns something like VMS Alpha executable, you will have to download unyaffs, and if you want to repackage it later on, mkfs.yaffs2,
to get the file's content, just run unyaffs filename.img, and you will have the file content right in the folder with the img file...
if you don't have a linux distro installed, you can simply get virtualbox, and download the latest ubuntu iso file... mount the file in virtualbox and install ubuntu (it's quite easy)...
oh and incase you need them some basic commands:
ls - lists current folder content
cd folder - allows you to switch to a specific folder, like if you type ls, and you get the folder android listed just type cd android... if you want to go back to your home folder, type ~/...
sudo command - allows you to run specific commands as superuser (root... you can also just switch to user root by typing sudo su, so you won't need sudo every single time)
rm file / rm -R folder/file - allows you to remove files and with the parameter -R also folders ;)
hope this helped
Touch Dual - 16 key version (mda touch plus) Android 2.2
Universal - VPA IV Radio 1.08.00, Cotullas Q3 ROM
Dream - Black
Haykuro's SPL, latest Radio, CM7