It's easy enough to add firefox profiles, but switching between them can be tedious, using a wrapped script, you can automate this task.

First you want to create a wrapper for firefox, this can be done easily two ways, either with update-alternatives or using a bash alias. To add a bash alias;

echo "alias firefox="/home/mike/bin/firefox-profiler.sh"" > ~/.bashrc

This will call our script instead of the path instance of firefox (alaiases take presidence)...

in our script now all we need to do is defrenciate a difference between the networks at home / work, this can be done on netmask or in my case if i'm using wireless or ethernet cable to connect.

Scirpt:
#!/bin/bash
# mike.j - 10/10/2011 - firefox profiler

checkEth0=$(/sbin/ifconfig eth0 | /bin/grep inet)
if [ -n "$checkEth0" ]; then
    /usr/bin/firefox -P "work"
else
    /usr/bin/firefox -P "home"
fi

If you are linking this script from the main menu or panels, you will need to either export the environment variable path or just use fully qualified paths inside the script.