I am a bit hesitant to get this going with all the command line stuff.
*EDIT* Also I have to run my router with a usb stick in it now all the time to use this?
Also do I need to do anything to the usb stick before plugging it into the router?
Format it with a specific partition system?
Use some ancient small usb stick. Format it as Ext2 and leave it in. Put your traffic stats there too, as well as John's marvelous backup script. Then, start from the very first post and work through the script variations to the end, which is a very good intro (and fun!). One feature is that it is hard to make a big mistake here. At the worst, you see ads, but except for the minute you are rebooting ("DAD!! stop fooling with the internet!) the rest goes on.
You don't want this in the firmware, because it is an evolving thing--just look at the pixelserve thread (which I haven't attempted).
Looking forward to what TLC has in his set-up script.