I uploaded my version to
http://jooshed.com/share/sw/4chan-1.15.xpi
The modifications from Rens latest build are as follows:
• Changed all names to 4chan Grab instead of not4chan
• Updated to work with boards.4chan.org & Firefox 3.6 betas
• Changed the directory label to a textbox, so you can type in the save path
If it doesnt automatically install, you'll have to download it and then drag it into your firefox window. Im not trying to take over this project, just offering up suggestions that I personally found useful. Let me know if theres any problems or suggestions and thanks to Ren for the help.