I'm sure it's in an obvious place but I can't find it. I see lots of documentation but no actual library.Thanks
Sorry that you had trouble finding it. The download link is a .zip on this page of the documentation (the beginning of section 5.) Please see link below.
I have clicked on the link. However I can't find the .zip file. Can you help me?
I have removed the link in Paul's post since it was out-dated.
You can find the Zip file containing the Arduino libraries for the Orangutan and 3pi robot under the "Configuring the Arduino Environment" section of the Programming Orangutans and the 3pi Robot from the Arduino Environment user's guide.