Ok here's what I've done
mount -t vfat -o uid=john,gid=users /dev/sda /home/john/flash

and i get back this message
mount: wrong fs type, bad option, bad superblock on /dev/sda,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

so i do dmesg | tail

sda: assuming drive cache: write through
sda: sda1
sd 1:0:0:0: Attached scsi removable disk sda
usb-storage: device scan complete
FAT: invalid media value (0xb9)
VFS: Can't find a valid FAT filesystem on dev sda.
FAT: invalid media value (0xb9)
VFS: Can't find a valid FAT filesystem on dev sda.
FAT: invalid media value (0xb9)
VFS: Can't find a valid FAT filesystem on dev sda.

and i still don't know whats wrong

other information
I'm using Debian etch

You should use /dev/sda1 instead of just /dev/sda to mount the 1st partition of the flash drive.

Regards

that worked i was able to use my flash drive