Would like to verify from the learned if the 580EX set on 'slave' could be triggered by any third party IR trigger? Or is there just something I'm missing? Is the ST-E2 the only one that could remotely actuate the 580?

No I haven't found any third party IR trigger that was able to trigger the 580EX in slave mode. But the Sigma 500 Super DG can be triggered if set to Slave at Channel 0.

I do hope that a third party version of ST-E2 exist. :)

Thanks man.
Yup I have the Sigma500Super as well and indeed could be triggered by other IR transmitters. Recently upgraded to the Canon580 and while tinkering with the unit (set as slave) I could not find a way to have it fire. ST-E2 or another 580 the only option?

If you want to utilize ETTL on your slave 580EX then ST-E2 or another 580EX is your only oprtion. Since you have the Sigma 500 Super you can set it to master on the same channel and group as your slave 580EX.

I have this set-up working well with 3 units 550Ex and the ST-e2, may I know why you want to try another IR? Is it because you have the IR existing already? The price of the ST-E2?

A friend had an IR that triggers the flash on slave mode, but gets it off on full blast, and NO ETTL communicaation. Is this what you want to do? He says there's no other trigger that does it on full ETTL mode.

As far as I knew, any strobes set to slave can be triggered by any IR as that is what the sensors read prior to firing.