Cool... ish
If you use the toslink from your TV, when your TV is making sound, it will go down the toslink cable to the splitter.
If you then tune your TV to the PS3, and have no sound output from the PS3
to the TV then the TV won't have anything to send down the toslink
Instead, the sound will be going out of the PS3 to the splitter, and then on to the surround sound system
It will cause a problem if both your PS3
and your TV are trying to output sound at the same time - a switched toslink splitter would get round that, but a) they cost more, and b) you would have to get up to switch the switch!
2 other things to note - I'm not sure if the HDMI cable carries sound (or if it's 5.1) - I use a HDMI to DVI convertor on my TV (no HDMI)
The PS3 can (apparently) only output sound on
either toslink
or RCA - not both at the same time. dunno why, but read it in the manual.
Final point - I've not tried any of this, as I have a different setup, but at £5 for a splitter it might be worth a punt
