Install from ISO

download ISO image

record it to CD or use for install to VMware/Xen VM

Prepare USB stick for install

download USB image - with '.usb'

record it to USB stick:

from Windows - try to download and use tool: http://devzone.sites.pid0.org/OpenSolaris/opensolaris-liveusb-creator

apt-get install usbimgtools

usbcopy2 <USB image>

iso2usb <ISO image>

From another Linux/Unix - try to use 'dd' tool with USB image