Also, Steve, would you consider using the Creative Commons Attribution-NoDerivs 3.0 license instead of a homemade license? I believe the CC BY-ND conveys most* of the same things you intended with your license, but it has the advantage of being pre-vetted by layers everywhere and the CC terms are very well understood (thus encouraging reuse in the ways you want, and ostensibly easier to enforce for the things you don't).

See: http://creativecommons.org/licenses/by-nd/3.0/

I say "most", because you also included the "so long as you do not charge anything for it" phrase in your license. Personally I'm not convinced that matters much in practice, as who is going to be able to charge for something you are giving away for free (and if they do, it'll be on a small scale, and do you really care?), and it's notoriously difficult to define things like commercial use, but if you feel strongly there's always the Non-Commercial variant: http://creativecommons.org/licenses/by-nc-nd/3.0/

Thanks!

Reference: http://learnvimscriptthehardway.stevelosh.com/license.html