Just for the heads up:
Save editing in the general side of things is not illegal. It's a file that's created by use of fair (like grabbing a save screenshot from the save file itself, you opened up the file you made from that point already so it's not really a serious crime off copying or opening etc.) There is a forum site by Game Genie that sells a USB save editing device for the PS3 that is actually accepted by Sony, with the cost of locking certain trophies or prevention of hex editing files that leads to things that are not accepted by public.
Save editing for malicious uses such as opening locked saves, multiplayer editing, obtaining trophies, or obtaining content locked within the disc that is only available by purchase as DLC (Capcom's games for example tends to have DLC content that's already in the disc but is only unlocked by purchase off the store like some sort of key access) is illegal because it's breaking the terms. In short, if you are hex editing a save for your single player experience "only" and has no connection to obtaining DLC content or changing multiplayer experiences or selling the file, you are fine.