Question: How do I data mine a pile of text to get keywords by usage? ("Jacob Smith" or "fence")

And is there a software to do this already? even semi-automatically, and if it can filter out simple words like "the", "and", "or", then I could get to the topics quicker.

Answer: 
You did not specify a technology you're working with, so I guess a shell script is also a possibility.

I've always been impressed by the word frequency analysis example in the [Advanced Bash-Scripting Guide](http://www.linuxtopia.org/online_books/advanced_bash_scripting_guide/textproc.html) (12-11)

The following for example fetches a book from project Gutenburg and writes out a word frequency analysis 'report':

```
wget http://www.gutenberg.org/files/20417/20417-8.txt -q -O- | 
sed -e 's/\.//g'  -e 's/\,//g' -e 's/ /\
/g' | tr 'A-Z' 'a-z' | sort | uniq -c | sort -nr > output.txt

```

Should be extendable to exclude words from a 'common' list (the, and, a...) etc.
I personally recommend Maui (<http://code.google.com/p/maui-indexer/>): it relies on KeA but extends it in a variety of ways. It is trainable and can use RDF formatted terminologies.