can't you loop through your string and check each charAt() whether its ascii is smaller  X and if so insert a #
http://processing.org/reference/String_charAt_.html

X being 91
http://de.wikipedia.org/wiki/American_Standard_Code_for_Information_Interchange#ASCII-Tabelle

afterwards split at all #

http://processing.org/reference/split_.html

A bit advanced, with regular expressions:

1. String str = "JFK and I Have Lot Of Capital Letters, OK?";
2. String re = "(?=[A-Z])";
3. String[] words = str.split(re);
4. 
   
5. println(Arrays.toString(words));
6. exit();

Or use some simpler RE (eg. "[A-Z]") to loop on the string, detecting quickly the capital letters.

Or to answer your subject line:

1. String re = "[^A-Z]";
2. String capLetters = str.replaceAll(re, "");
3. print(capLetters);

Okay. I see. Thank you!

I haven't used ascii before so from the what I've looked up it looks like the the dec representation of lowercase letters is between 97-122 and uppercase is 65-90 so I just change each letter to dec form and check if it is in that range. Correct? How do I get the dec form?

Thanks.
McK

1. char a = "FooFoo".charAt(3);
2. println(a);
3. println(int(a));
4. exit();