External HD issues (PC vs. Mac)

Hi, I've got a desktop PC with an external HD nearly full, and a new Macbook. When I try to hook up the HD to the Macbook, it insists that I need to reformat the drive (presumably because it's only been used with the PC up till now). I realize the NTFS formatting that exists on the HD, but I'm terrified that reformatting the HD will erase the entire thing and lose all my work. Any ideas?

You can consider using NTFS-3g.
It allows you to read and write to the HD with NTFS format.
Hope this may help^^

Formatting your external drive will certainly erase all your data. Can you copy it to your mac then reformat it before copying your data back again?

Sawday - not nearly enough room on the Mac, I wish I could do that!

How do you use NTFS-3g?