How To Jailbreak PS3 on 3.66 only
http://www.jailbreakblog.net/
STEP 1:Plug a USB stick into your computer
STEP 2:Create a folder in the root of the USB stick called PS3
STEP 3:Create a folder inside the PS3 folder called UPDATE
STEP4:Download PsgrooveV1 Tool http://www.mediafire.com/?1vti2tnd1uhec2x
STEP 5:Run as Administrator and click on generate button it will generate PS3.66JBUPDAT.PUP
STEP 6: Move PS33.66JBUPDAT.PUP to the directory UPDATE that you just created on the USB stick
STEP 7:Plug the USB stick into your PS3
STEP 8:Navigate to Settings Tab
STEP 9:Choose System Update
STEP 10:Choose Update via Storage Media
STEP 11:It will say it found Version 3.66-jb
STEP 12:Choose OK
STEP 13:Accept Conditions and Install Update
STEP 14:After less than a minute, your PS3 will update, beep 4 times then shut down.
STEP 15:Power up your PS3 (You will have to do it on the console and not by the controller)
STEP 16:Your PS3 is now jailbroken
Tool Link
http://www.mediafire.com/?c73y3x45uqz4o7e