Jailbrakers and unlockers DO NOT RUN! Apple released iTunes and iPhone update today. iTunes is safe, but @westbaer points out that iPhone 3.1.3 closes the usb_control_msg exploit, used by blackra1n. It also looks like it’s just bug fixes and perhaps prep for the new ipad. Nothing I can’t wait for. I hope any 3gs or touch 3g owners have their shsh blobs saved through cydia or umbrella.
UPDATE: for original (2g) iPhone users can use the latest Redsn0w to update your phone to 3.1.3. you must feed it the 3.1.2 ipsw.
UPDATE 2: new pwnage tool or sn0wbreeze to break 3.1.3 on all but the newest devices (new bootrom 3gs and touch 3g), but it’s a pain and not worth it with 3.2 just weeks away.