How to make a USB bootable Debian installer..

First, you need to install Grub2 on a USB drive.   That is usually done with a command like this:

grub-install /dev/sda1 –root-device=/media/usb0 –no-floppy

Then, edit the grub.conf file like so:

nano /media/usb0/grub/grub.cfg

Add the following:

menuentry “Debian Wheezy Installer” {
set root=(hd0,1)
linux /debian/vmlinuz root=/ boot=USB vga=791 rootdelay=10 udev
initrd /debian/initrd.gz

If you intend to install the 64-bit version of Debian, you will want to download the files here:

Place the boot.img.gz, initrd.gz, and vmlinuz files into the /media/usb0 folder.

Reboot, and you should be able to boot up Debian from your USB stick.