on debian and also ubuntu you should always try to install .deb packages and not .rpm,
so you need first a program called "alien" that can convert the rpm in deb, install it by typing:
apt-get install alien
then go to the directory where the file called "jdk-6u2-linux-i586-rpm.bin" is and type:
./jdk-6u2-linux-i586 -x
to extract the .rpm files, now there should be a lot of .rpm files in this directory, you have to convert all of them with alien into .deb files, like that:
alien --scripts --keep-version -d *.rpm
(where * stands for each files name)
if you have converted all of them you just have to install each one by:
dpkg -i *.deb
