RouterOS does not support USB stick boot. Why?
should not be to hard to implement.
Maybe v7 solves this. Would be handy to install from an USB stick. I do not have CD/DVD drive around.
Easy2Boot does NOT support RouterOS
See List1d
http://www.easy2boot.com/add-payload-files/list-of-tested-payload-files/
This is not a new request:
http://forum.mikrotik.com/t/putting-iso-on-usb-stick/18557/1