Hackers not part of the official iPhone Dev Team have released an iPhone and iPod Touch jailbreak that's based upon the Safari TIFF image exploit we first saw a few days ago. There are a few major things wrong with it, which means this isn't exactly ready for normal people to use yet. We've been researching it all day, and have come to the conclusion that we can't recommend this jailbreak to anyone except people who recompile their kernel on the weekend for fun.
First off, if you apply this patch you won't be able to sync any data to iTunes in its cracked state. To sync again, you're going to have to "delete the symlink Media [directory] and rename OldMedia to Media." Or restore to the previous state, which of course means you will lose the jailbreak.
Also, just to apply the patch, you're going to have to be familiar with IPHUC, a command line utility that that lets you browse your phone's file structure. It also involves directory manipulation when you're inside the phone, also not a basic task. This alone requires you to have basic linux command line knowledge, and rules out most of the regular folks who just want Super Mario on their phone.
In addition to this, if you have an iPhone, this tool won't activate it. The iPod touch doesn't require activation.
So our recommendation is to wait. This is a good start, a step in the right direction, but wait until a much friendlier jailbreak is out. (Additional reporting by Jesús Díaz) [toc2rta]