I am unaware of any Windows utilities that can work with 11.1 USB images. Google searches would turn up the old OpenSolaris USB creator that community members wrote for Windows, but we changed to the GRUB2 boot loader in 11.1 so that utility almost certainly will not work.
Note that the AI image you mention is probably not what you want, it's set up only to run the automated installer, not as a generally useful system.
I'd suggest just download one of the VM images from http://www.oracle.com/technetwork/server-storage/solaris11/downloads/virtual-machines-1355605.html and run Solaris within that to try it out. If you're really set on trying out the USB images then you can process them from the VM.