Ubuntu 7.10 USB installation tutorial:

# Grab the Ubuntu 7.10 ISO and burn it to a CD
# Insert the CD and your USB flash drive
# Reboot your computer into Ubuntu from the Live CD
# Open a terminal window and type sudo su
# Type fdisk -l to list available drives/partitions. Note which device is your flash drive (example: /dev/sda) Throughout this tutorial, replace x with your flash drive letter. For example, if your flash drive is sdb, replace x with b.
# Type umount /dev/sdx1
# Type fdisk /dev/sdx

* type p to show the existing partition and d to delete it
* type p again to show any remaining partitions (if partitions exist, repeat the previous step)
* type n to make a new partition
* type p for primary partition
* type 1 to make this the first partition
* hit enter to use the default 1st cylinder
* type +750M to set the partition size
* type a to make this partition active
* type 1 to select partition 1
* type t to change the partition filesystem
* type 6 to select the fat16 file system
* type n to make another new partition
* type p for primary partition
* type 2 to make this the second partition
* hit enter to use the default cylinder
* hit enter again to use the default last cylinder
* type w to write the new partition table

# Type umount /dev/sdx1 to ensure the 1st partition is unmounted
# Type mkfs.vfat -F 16 -n ubuntu710 /dev/sdx1 to format the first partition
# Type umount /dev/sdx2 just to ensure the 2nd partition is unmounted
# Type mkfs.ext2 -b 4096 -L casper-rw /dev/sdx2 to format the second partition
# Remove and Re-insert your flash drive
# Back at the terminal, type apt-get update
# Type apt-get install syslinux mtools
# Type syslinux -sf /dev/sdx1
# Type cd /cdrom
# Type cp -rf casper disctree dists install pics pool preseed .disk isolinux/* md5sum.txt README.diskdefines ubuntu.ico casper/vmlinuz casper/initrd.gz /media/ubuntu710/