I hope this will help any one mount their usb flash key device, everything I did as “root”. Some devices will be supported and some are not. You can check on www.linuxhardware.net to see if device supported.
UPDATE: USB flash drives automount in fedora core 3 which means is plug and play.

First plug your usb card reader and to make sure your device was detected go to System Tools > Hardware Browser > enter root password and it will display your hardware information then go to > Hard Drives and it should be listed under /dev/sda.

Open your favorite terminal....btw this works in gnome and kde.

[[email protected] imdeemvp]$ cd /mnt/ <-as user cd yourself to the mnt folder and become root to create directory
[[email protected] mnt]$ su
Password:
[[email protected] mnt]# mkdir usbflash <- this created a directory in the mnt folder

[[email protected] mnt]# ls /mnt/ <-this command listed all my directories the mnt folder
cdrom cdrom1 floppy usbflash

[[email protected] mnt]# mount /dev/sda1 /mnt/usbflash <-this is the command to mount flash card reader

[[email protected] mnt]# ls usbflash <-this listed all the info in my usb flash card and this was the output:
bootex.log dns.bmp games and keys LinuxDocs01.21.04 pc's
dns2.bmp Documents LinuxDistributions_eBay my pics programs

then i just copied this to my home folder and i was done!

[[email protected] mnt]# umount /dev/sda1 /mnt/usbflash <-this unmounted my usb flash card
umount: /dev/sda1: not mounted
[[email protected] mnt]# exit
[[email protected] mnt]$