Running Iceweasel-5.0 And Iceweasel-4.0 Together On Squeeze

I'm running iceweasel-4.0 installed from http://mozilla.debian.net/.
Related packages are :
iceweasel 4.0.1-1~bpo60+1
xulrunner-5.0 5.0~b2-1~bpo60+1
libmozjs5d 5.0~b2-1~bpo60+1
If you want to try out iceweasel-5.0 and keep iceweasel-4.0 as well do the following :

Add the following line to your sources.list :
deb http://mozilla.debian.net/ squeeze-backports iceweasel-5.0
and run as root apt-get update .
We only need to download the deb package to get iceweasel-5.0, we don't install it ( otherwise iceweasel-4.0 will just be upgraded ). As root run :
apt-get install -d -t squeeze-backports iceweasel
This will download package iceweasel_5.0~b2-1~bpo60+1_amd64.deb in my case. You can find it back inside /var/cache/apt/archives .

As root run the following commands :
mkdir /usr/local/iceweasel5
dpkg-deb -x iceweasel_5.0~b2-1~bpo60+1_amd64.deb /usr/local/iceweasel5/
ln -s /usr/lib/xulrunner-5.0 /usr/local/iceweasel5/usr/lib
ln -s /usr/local/iceweasel5/usr/bin/iceweasel /usr/local/bin/iceweasel5

To verify :
which iceweasel5 gives :
/usr/local/bin/iceweasel5

Run iceweasel5 -P and create a new profile.

Make a shortcut to run iceweasel-5.0 :
iceweasel5 -P "profilename" -no-remote