Installation of Freebsd on external hard drive

[Marco Calviani]

Hello freebsd-mobile,
i'm a quite experienced Debian laptop user using an Acer Travelmate 8005. I
would like to install freebsd on an external USB or Firewire HD and choose
which OS use at startup (maybe within the GRUB loader). However i'm a BSD
newbie.
Could you give me some hints on how to perform this task? What option should
i choose for the bootloader?

Thanks in advance for the help,
MC