Sorry to necro post, but if anyone is in the Boston area, there's a 70mm screening of 2001 this Saturday and Sunday. It's at the Somerville Theater. I wish I could go, but this weekend is unfortunately not good for me. :(
Anyway, for those who may be interested: http://feitheatres.com/somerville-theatre/2001-a-space-odyssey-in-70mm-this-sat-sun-only/