Linux to the rescue (and request for help)

[Travis Roy]

So a friend of mine keeps his livelyhood on an external USB hard drive. The
drive came formatted FAT32 and he was using it on his mac.

He didn't wait for his mac to shutdown fully before unplugging the hard drive.
The mac didn't like the drive anymore, Windows kept saying that it was corrupt
and it needed to be reformatted, not letting me get access to the information
on the drive.

After plugging it into my linux box it saw the drive, after mounting it I am
able to get to the information and copy it off.

My question is, since it's nearly full, I don't have a lot of space to store
his data. Is there any way to "fix" it without having to copy the data off.
I'm making copies anyway and burning it to DVD for him, but that's still a lot
of stuff, I'd rather not have to copy it all back over.

It also has some weirdness. A df shows this:

[root at scootz proc]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                      75762792  51838856  20075336  73% /
/dev/hda1               101086     15223     80644  16% /boot
none                    257556         0    257556   0% /dev/shm
/dev/sda1             78129056 -590295810358704317216  79463552 101% /mnt/temp

Other info:

[root at scootz usb-storage]# more 0
   Host scsi0: usb-storage
       Vendor: Seagate
      Product: ST94811U2-RK
Serial Number: 354A564D42514C54
     Protocol: Transparent SCSI
    Transport: Bulk
       Quirks:

usbcore: registered new driver usb-storage
USB Mass Storage support registered.
SCSI device sda: 156301488 512-byte hdwr sectors (80026 MB)
sda: assuming drive cache: write through
 sda: sda1
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0