I read Ender's Game for the first time last month [yes, it's fantastic, and yes, I'm an idiot for not reading it sooner]. I wasn't aware of the book's plot until then, so I had gone through 83 chapters of HPMOR without realising it paid homage to Ender's Game [let alone the extent to which it did so]. Are there references to other books [or films or other forms of media, I guess] which I might have missed?