Need help how to format an external HD in ext3

Hi everyone, I need your precious help.
Before explaining my situation I need to say that I am new to Mac and I have zero Linux knowledge, so please be patience with me.
I need to use an external hard disk to copy large files on my mac to transfer it to my media center. As far as I could find out googling, I need to format this HD t ext3. NTFS doesn't work on Mac, FAT has size file limitation and my media center doesn't support HFS+, but it does support ext3.
I still couldn't find out how to format an external hard disk to the ext3 format using my Mac. Is there an application that does this easily? If there is no application and the only way is using command lines I will need a full beginner's help...

Thanks!

Fabio

There is an application called ext2fsx which installs a driver in os x to mount ext 2 or 3 drives. However it is not very reliable in my experience and probably will require use of terminal.

Here is what worked for me:

1) Download ext2fsx.

2) Install, reboot. Upon reboot you may or may not see your drive mounted. If not you will need to do the following.

3) Create a directory in /Volumes to mount the drive in, like /Linux

4) Open up terminal and mount the drive with the following command:
sudo mount_ext2 -o rdonly -x /dev/disk1s1 /Volumes/Linux. You will need to replace disk1s1 with the correct disk/partition (Identifier) of your Linux drive. To find the identifier, first type "diskutil list" in terminal, find your EXT drive, and on the far right it will show you the identifier.

Once again, in my experience I have found this program to be unstable and unreliable. Good luck and let me know if it worked for you.

What I have done is to partition the drive in NTFS, attach it to the media center computer, create a shared folder on the partition and check the option "Allow network users to change my files"

Now using smb on my mac I mount it and easily drop files onto this partition.
Of course this is easy if both the computers are on the same network/router, which is my case. Hope this helps.