This is a small (but detailled) guide about how to root you HTC Chacha if it is S-OFF. This method is ONLY for S-OFF phones.
(1) Download Mikevhl's CWM recovery (PH06IMG.zip) from this thread to your phone's SD card (in the root of the sdcard).
(2) Download Superuser zip from this thread, also to the root of your sdcard. Choose "su-22.214.171.124-ef-signed.zip". (EF is for Eclair, Froyo and later)
(3) Go to settings -> Power -> uncheck "Fastboot" Turn off the phone Hold VOL Down + Power for 5 seconds
(4) The phone will boot to HBOOT. It should show S-OFF.
If you see S-ON, it won't work.
Following a few seconds, it will scan automatically for a PH06IMG.zip file on sdcard and propose you to install it.
(5) Press volume Up to start flashing the file (the CWM recovery)
(6) Once done, when asked, press power to reboot the phone.
The phone will then reboot normally.
(7) Rename the PH06IMG.zip on your SDCard to PH06IMG.zip.CWM for example.
(8) Turn off the phone again, and Hold VOL Down + Power for 5 seconds, to get back again to HBOOT
(9) Once in HBOOT, the phone will scan again for a PH06IMG.zip on the sdcard. It should fail (as we renamed the file).
(10) Use vol-up/vol-down to select "RECOVERY" in the menu and press "Power".
This will get you to CWM recovery
(11) Using the keyboard arrows and "Return" key to select, choose "Apply zip from SDCard", then "Select zip" (or something like that). Choose the file su-126.96.36.199-ef-signed.zip and press return. Then choose "Yes".
(12) Once flashed sucessfully, press "<x] DEL" to get back to the main menu, and select "Reboot" to reboot your phone
That's it, the phone is rooted :-).
You can try for example Android Terminal Emulator, and type "su", Superuser will popup, give access and you should be root.
Credits: - Mikevhl for porting CWM recovery to Chacha - ChainsDD for Superuser