Try to follow this one.
* Find you USB Drive.
# grep -Ff <(hwinfo --disk --short) <(hwinfo --usb --short)
Creating the partition
For me my USB was only design as Live Bootable Disk, in create the new partition I decide to delete current parting and create new one.
* Selecting the Disk
# /sbin/fdisk /dev/sdb
* Atfer selected, issue
m option to display the help
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
* Delete the partition:
Command (m for help): d
Selected partition 1
* Create Partition
Command (m for help): n Press n and hit enter
Command action
e extended
p primary partition (1-4)
p Press p and hit enter
Partition number (1-4, default 1):
Using default value 1
First sector (2048-3948543, default 2048): Just hit enter here
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-3948543, default 3948543): Just hit enter here
Using default value 3948543
* Tag the Partition as bootable.
Command (m for help): a Press n and hit enter
Partition number (1-4): 1 As you create only partition press 1
* Verify the partition you create.
Command (m for help): p
Disk /dev/sdb: 2021 MB, 2021654528 bytes
42 heads, 4 sectors/track, 23503 cylinders, total 3948544 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0001f52c
Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 3948543 1973248 83 Linux
INFO: As you notice Boot colunm has start(*)
* Finally you done creating partition, now write the partition in the disk.
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Now, write the Live ISO to your USB
# dd if=/home/syntax3rror/Downloads/Fedora-17-i686-Live-KDE.iso of=/dev/sdb
1423360+0 records in
1423360+0 records out
728760320 bytes (729 MB) copied, 286.532 s, 2.5 MB/s
YEHEY, Your done, you can now able to boot Fedora17 live in your USB. just be sure to change the boot priority of your system bios.
IMPORTANT NOTE
* Besure the device NOT mounted. If ever mounted you can umount /dev/sdb
* Besure to backups all you important data in you USB.
* Besure to use /dev/sdb as device name and NOT /dev/sdb1
Happy Reading and Post if works for you