I've put together a tutorial on making a portable version of Eclipse with no external dependencies. You can read the full article here:

http://animalija.sopca.com/2009/11/04/eclipse-na-usb-kljucu/

Since the article is in Slovene, you can read the poorly translated page here:

Translated Page (Google Translate)

Mind that you'll have to see the original post, since Google Translate mangles source code as well.