I do not want to over-complie it, but that is a fantastic link, worth keeping an eye during the day. Oil and copper are great indiors of risk, rising prices is usually risk off prices is usually risk on.
Http://finviz.com/futures.ashx
Additionally bond prices are significant, particularly treasuries (t-bills), decreasing prices is usually risk off, and vice versa. These are displayed in preceding link.
As mentioned by others keep an eye on equities, particularly the SP 500. Additionally in currencies, AudJpy is a great one.
Its best...