It will also work correctly if you are on a pre-rooted kernel. It will install superuser, busybox, and clockworkmod.
Here's 2.5.0 of the one click root, now with the clockwork redirector integrated.
I cleaned up noobnl's script a little bit and ensured that adbd would run as root when booted into recovery. Also made sure we symlinked every single applet that recovery's busybox provides.
Now the one click also avoids pushing playlogo unless it detects that you have the old joeykrim root installed, to avoid any potential issues with future froyo releases.
Linux and Mac users users chmod +x run.sh and run it
Here's 2.2.7, that simplifies the root process thanks to the discoveries here: http://forum.xda-developers.com/showthread.php?t=800483
I also increased the timeout after running the root (fails less), moved more things to /system/xbin to reduce the risk of breaking things, and removes all the old files leftover from joeykrim's root (including his modified playlogo that runs at boot every time).
It also means your system will no longer be mounted as read-only every time you reboot and there's no more problems with jk-su overwriting your existing su binary.
1. you need samsung galaxy s drivers
32-bit drivers: http://firon.net/xda/Samsung_Mobile_...00_Epic_4G.zip
64-bit drivers: http://firon.net/xda/usb_drivers_GalaxyS_x64.zip
2. push MENU, select Applications > Development, then enable USB debugging.
3. extract and run run.bat
v2.2.4 added busybox and the remount script and fixes sprint animation not showing
2.2.5 superuser.apk & su added!
v2.2.6 installs busybox to xbin