I don’t watch hardly any TV, and when I do it is not a reality show, especially not one of the star search variety like American Idol. When I saw Nick Hodges post about Opera, I first figured it was the Web Browser. Then when I figured it was the musical style, I [...]

I like math, but might not know as much about it as some real math nuts.  I was reading the web comic XKCD, which has a lot of math jokes.  I read this comic titled e to the pi times i (language warning) which says if you take e to the power of π times [...]

It is kind of complicated actually.  There is some stuff that is straight forward.  Published before 1923 is public domain. Anything else has other criteria.  Here is a guide.  That is all for the US, so it may be different elsewhere.
Here are a couple sources of Public Domain documents in ready to use electronic format:
Project [...]