Herb Sutter writes on C++ closures, which have been accepted as part of the next C++0x standard. This means C++ is joining Java in supporting closures. My first introduction to closures was Javascript, and I think it will be great for the other mainstream languages to support them. Of course, it will probably be a few years until closures are widely used, as was the case for C++ and Java templates/generics.
If you are interested in more details, be sure to read the comments at the end of Herb's blog post — there's some good examples and discussion.