Have you heard anything about this sinno?
[video=youtube;JRDsGHLZRA4]http://www.youtube.com/watch?v=JRDsGHLZRA4&feature=player_embedded[/video]
i got mine in uk £17.00 and it can do up grade and down grade will post link if im allowed works great had mine 2months now no probs
Here is another dongle which will jailbreak your PS3,but this has now got an added dimension it can also downgrade from 3.50 firmware,its rediculously cheap and by all accounts from the guys in the know it works.
I have already ordered one
HERE