[AT&T, Rogers HTC One X, Telstra One XL] boulder_dave:
Here's how I tried to flash the RUU (failing):

C:\Users\dkabal\Downloads\android\sdk\platform-tools>adb reboot-bootloader
* daemon not running. starting it now on port 5037 *
* daemon started successfully *

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot oem lock
...
(bootloader) Lock successfully...
(bootloader) TZ_HTC_SVC_DISABLE ret = -2228225 (0xFFDDFFFF)
FAILED (status read failed (Too many links))
finished. total time: 0.945s

This booted me into CM unexpectedly

C:\Users\dkabal\Downloads\android\sdk\platform-tools>adb reboot-bootloader

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot oem rebootRUU
...
(bootloader) Start Verify: 0
OKAY [ 0.059s]
finished. total time: 0.062s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
OKAY [ 24.835s]
writing 'zip'...
(bootloader) zip header checking...
(bootloader) zip info parsing...
FAILED (remote: 24 parsing android-info fail)
finished. total time: 34.936s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
FAILED (remote: 02 data length is too large)
finished. total time: 0.020s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
FAILED (remote: 02 data length is too large)
finished. total time: 0.020s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
FAILED (remote: 02 data length is too large)
finished. total time: 0.020s

For some reason, if I didn't reissue the below command, subsequent flashes would fail, even though I was still in the black screen with HTC logo mode

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot oem rebootRUU
...
(bootloader) Start Verify: 0
OKAY [ 0.060s]
finished. total time: 0.063s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
OKAY [ 24.421s]
writing 'zip'...
(bootloader) zip header checking...
(bootloader) zip info parsing...
FAILED (remote: 24 parsing android-info fail)
finished. total time: 34.514s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
FAILED (remote: 02 data length is too large)
finished. total time: 0.024s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot oem rebootRUU
...
(bootloader) Start Verify: 0
OKAY [ 0.059s]
finished. total time: 0.060s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
OKAY [ 24.132s]
writing 'zip'...
(bootloader) zip header checking...
(bootloader) zip info parsing...
FAILED (remote: 24 parsing android-info fail)
finished. total time: 34.234s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot oem rebootRUU
...
(bootloader) Start Verify: 0
OKAY [ 0.059s]
finished. total time: 0.063s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot flash zip OTA_EVIT
A_UL_JB_45_S_Cingular_US_3.18.502.6_0.24p.32.09.06_10.130.32.34_release_3061616b
cty3drvawwo01k.zip
sending 'zip' (645841 KB)...
OKAY [ 24.144s]
writing 'zip'...
(bootloader) zip header checking...
(bootloader) zip info parsing...
FAILED (remote: 24 parsing android-info fail)
finished. total time: 34.232s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>fastboot reboot-bootloader
rebooting into bootloader...
OKAY [ 0.065s]
finished. total time: 0.070s

C:\Users\dkabal\Downloads\android\sdk\platform-tools>

So I'm not sure what to do next. Flashing RUU doesn't seem to work. bootloader says I'm still S-OFF (whatever that means), now "RELOCKED", CID still 11111111, and hboot still 1.09.

Thanks again for taking me through this,

Dave