First, make sure you use the mod_rewrite flags QSA and L
then because the query arguments are being secretly passed still as variables you can use like normal ( eg. $_REQUEST['first'], etc. ) simply develop a function in place of the actual URLS.
eg.
echo "blablabla.com/first/second/third/";
would be
echo "blablabla.com/". ReWrite("first", "second", "third) ."/";
Then in this function you can make a check for a mod_rewrite variable being set to ON or OFF.
Then based on that you can deliver the urls...
if mod_rewrite was on, the above code would output:
blablabla.com/first/second/third/
if mod_rewrite was off, the above code would output:
blablabla.com/index.php?variable1=first&variable2=second&variable3=third
and because it's a function, you can change variable names to be output based on what first variable was sent in for example, like a reverse mod_rewrite
That's how I'd do it, but then again, I'd just say get mod_rewrite or don't use this app
