Well we are diverging from the theme, but the proper form of that is

  #define O_HAI {
  #define KTHXBYE }

You can even go a little further and use trigraphs, which is one of those ancient features that most people have forgotten because it doesn't make much sense anymore. ??< and ??> are equivalent to { and } in C, which could be handy for further obfuscation.

http://en.wikipedia.org/wiki/Digraphs_and_trigraphs