So… when I’m writing things in most other programs I hit Ctrl-S a lot out of habbit. Other people who are used to editing documents and code offline may do the same thing and it will contribute to a frustrating experience.
Not being awesome at javascript myself, I looked and found this indicating it may be possible to capture it: http://stackoverflow.com/questions/93695/best-cross-browser-method-to-capture-ctrls-with-jquery