Regardless of some unscrupulous websites out there, Dev-Team reminds us that jailbreak solutions for iPhone firmware version 3.1.3 on new devices like the iPod Touch 3G don't exist! Unlock solutions for baseband version 05.12 do not exist! Scam sites will take your money and give you older software that was already released for free.
Unlocking and jailbreaking software is always released free of charge. Currently baseband 05.11 can't even be unlocked on iPhone OS 3.1.3. If you upgraded your firmware using the official Apple 3.1.3 software you'll just have to be patient while the Dev-Team finds a way.
Progress has already been made, as Dev-Team commenter sherif_hashim has discovered a promising crash in the new baseband. The Dev-Team is looking into it and could possibly come up with a working unlock solution. Right now there's no telling how long it might take.
Scam sites are counting on iPhone users stuck without a jailbreak to be impatient and spend a few bucks on nothing. Don't be fooled!