or use redsnow?ill link u my guide
My iOS device is...
Running iOS 5.0, 4.2.9-10, or 4.3.4-5.
Not right now. Follow @iphone_dev for updates.
(There is a beta, tethered jailbreak for non-iPad 2 and non-iPhone 4S devices here.)
Running iOS 4.2.6 through 4.2.8, or iOS 4.3 through 4.3.3.
Open JailbreakMe on your device itself.
On iOS 4.1 through 4.2.1.
Use redsn0w and the IPSW for your firmware.
I have a iPhone 3GS iOS 5.0.1 also. Download the IPSW 5.0, download the newest version of redsn0w. Do "Select IPSW" and select the 5.0. This will do a tethered jailbreak on your iOS 5.0.1 iPhone. When that is done, do as the post above me says, go into cydia and download "SemiTether".