PwndevTeam has just released Ac1dSn0w beta 2 and fix legal issue, you can jailbreak iOS 5.0.1 and 5.0 using ac1dsn0w beta 2.
iPod Touch 4 G
How to jailbreak iOS 5.0.1 and 5 with ac1dsn0w beta 2?
Step 1. Download Ac1dSn0w from our Download page
Step 2. Run Ac1dSn0w and you’ll see the following screen
Step 3. Connect your iOS device to your Mac then turn your iOS device off.
Step 4. Click ‘Show Assistant’ and follow the screen instructions to enter DFU Mode.
If you click the “Show Console” and you’ll see some device related information and the current state of your jailbreaking process.
Step 5 . Once you’re in DFU Mode just hit the ‘Jailbreak’ Button and wait until it’s done (the device will reboot).
Step 6. Put your device again into DFU Mode (Step 5) and hit the ‘Tethered Boot’ Button.
Step 7. Please wait a moment or 2 for the a white Cydia icon to appear.
Step 8. Click on the white icon and wait for Cydia to initialise and close.
After the process is complete and close it then reopen Cydia Your device should now be jailbroken with Cydia Installed.