Canon Speedlite Questions

[Roosta]

I'm after so more practicle advice than what I can take from the Canon Speedlite pages.

I would like to have a flash, I wouldn't use it much, so the 430EX 11 seems to fit the bill, add to that, at $284.00 from DWI rather than the Aussie price and a 580EX 11 that would be nice, but I have to be realastic and say I would hardly use it to it's fullest.

Can the 430 be fired off camera, as in mounted on its hotshoe plate supplied?

It says on the Canon Aus site Quote "--------------------------------------------------------------------------------

Wireless SlaveThe Speedlite 430EX II can be used as a wireless slave flash unit triggered by an appropriate master flash unit. The small size and high power output make it an ideal slave flash for creating a portable studio with multiple flashguns.
" end quote.

So can I use it off camera? If so, do I need to buy a trigger device, or will it have to be facing the camera and my 50D's in-built flash fire it (Not really what I want)
I see you can get a cable to trigger it, but that's not really the best for what I wan't to use it for.

My main thoughts for use would be a little for light bounce/fill in longer exp low light shots, maybe the odd time to use it at night, kids-family and the likes.

Can any one simply explain E-TTL to me to please, I under stand the acranim, but not the techknowledgly totaly.

Is there a viable third party brand/product I should consider?

Any advice would be greatly appreciated.