Sony today released the update for the PS3 firmware version 3.42 whose sole purpose is to block the hacking of the PS3 (both for backups and for homebrews). The mandatory update for anyone who wants to continue playing using the Playstation Network and confirmed that PSJailbreak (PSGroove / PSFreedom) no longer have any effect.
Not updated the console if you want to keep the possibility of making backup copies via USB hard disk!
If you want to go the same online on the PSN (at your own risk) with the firmware <= 3.41, there is a very simple method that for now (07/09/2010) works to bypass the firmware check upon connection.
The only thing to do is change the DNS give her settings of the PS3 and set it at this address:
Warning! On 09/09/2010 the method has stopped working and there is no way to go online with firmware lower than that required by the PSN (3.42). If a way is found in the future, we will write it on the blog.
There is no way of knowing if another method can also be found for firmware 3.42 and later. Soon we will publish an article to clarify what is happening (clones of PSJailbreak, devices used, backup manager, etc) and the methods to perform the Jailbreak on PS3. Read on the blog or follow us on twitter!