In case somebody does not know, there is a little problem to install OpenSolaris 2008.11 on USB. After the installation, you will not be able to boot the new image, because of problems with the new grub implementation. So, you can see here a post with the description: “grub that allows booting from a zpool without devid, see CR 6770866”.
Download this patched version, and here the instructions to install it. The default installation of 2008.11 needs a minimum disk of 2.6 (with the gnome desktop), i did a installation on a 4GB pen drive, and did remove all the gnome packages. After that, a simple zfs send of the rpool, and receive on another 2GB rpool.
peace.