I know you said you don't want command line, but for your purposes 'rsync' is ideal.
It's not to difficult to learn, something like this will do a backup:
Code:
rsync -avHSx --delete-after /home/username /mnt/usbdrive
where '/home/username' should be replaced with your home directory and '/mnt/usbdrive' with the mount point of the USB drive.
The --delete-after means it will delete any files on the USB drive that don't exist in your home directory (useful for repeated use if you don't want to keep files backed up previously that you have deleted in your home directory).
While you are at it you might also want to look into encrypting your USB stick first, so your backed up data is safe, have a look here for a quick guide:
http://home.linuxtech.net/tips+trick...ni_how-to.html