I'm currently trying to send my browser the command to go fullscreen with "xdotool key F11" which I inlcuded in a seperate script that is called in rc.local. The script includes a sleep to give the system time to load and then executes the mentioned command. But it doesn't work. Is there another way to run a script directly when the desktop is loaded?
The answer to your problem is easier than the answer to your question.
(Although thas most likely to be just 'YES')
Most browsers will accept commandline arguments.
Midori has the option '-e Fullscreen' which will do just what you wish for.
For Firefox it's a bit more work, but seems to work fine once its done:
It remembers the last window state. We can use that...
Create a new profile by running firefox -no-remote -ProfileManager
Name it for example 'fullscreen'
run firefox with the new profile (firefox -no-remote -P 'fullscreen'), move to full screen (F11) and then close it while in fullscreen (use ALT+F4)
firefox -no-remote -P 'fullscreen'
To make sure it will allways be in fullscreen, you could remove write-permisions on the localstore.rdf file in the firefox profile. I'm not sure what else gets stored in that file so it could mean DATA LOSS!
If you choose to try it, here is how IF your new profilename is fullscreen:
chmod a-w ~/.mozilla/firefox/*.fullscreen/localstore.rdf
This readonly option could be applied to your regular firefox profile files, but I'd do some heavy testing first!