> can I get this grub to boot from an iso-file like grml1.0 or even
> Knoppix or BartPE on the flash-pen ?

Using grml1.0 to boot from grml1.0's iso is easy, just use the bootfrom cheat code, or check this out:

boot grml_iso from HD http://xpt.sourceforge.net/techdocs/nix/live/grml/grml04-Boot/ar01s02.html

Grub on USB Stick http://xpt.sourceforge.net/techdocs/nix/live/grml/grml04-Boot/ar01s05.html

To locate the booting USB is more difficult than HD, so you might want to check out grml's booting with UUID option:

http://xpt.sourceforge.net/techdocs/nix/live/grml/grml14-ReleaseRelatedIssues/index.html#_Wishlist_automount_by_names

To use grub or grml as a general purpose iso-file boot loader, I doubt that it is possible, but I'm ready to listen.

FYI, you might also find the following urls helpful.

A GRUB Tutorial http://xpt.sourceforge.net/techdocs/nix/disk/boot/boot06-Grub/ar01s06.html

Pen Drives under Linux http://xpt.sourceforge.net/techdocs/nix/disk/pen/

thanks

xpt