Is infrared blocking film effective in reducing temperature inside a room?
My house has no central air and lots of huge windows on the south, so it gets a bit toasty in the summertime.  

I installed window film (brand is "Vista Window Film" if it matters).  I don't know what it does in terms of which part of the spectrum it blocks (IR or not?).

It has done a fantastic job.  It colors the view just a bit, though you only really notice when comparing against a non-tinted window.  Temperatures are bearable in the summer now.