I saw this one on the Twitter stream via @jmspool and I wanted to repost it because I vehemently agree that nested menus are a usability nightmare.
However, I don’t necessarily agree with the proposed solution — all those options on one menu doesn’t make finding and choosing an option much easier.
This is a tricky one. I recently started a new job where I inherited a nested navigation scheme, and, believe me, figuring out an alternative is not easy (nor a high priority with all the other work we’re doing.) But because these menus open on hover, I am constantly accidentally opening a different menu while mousing to the nested options.
I propose simplifying navigation, considering what the most important/common actions are, and making those accessible from the main screen. If that’s not possible, at least consider making the menu open on click rather than hover.