I am thinking about getting a wireless radio sender to trigger slave
flashes, along with 5-6 matching receivers, and set up a battery of
cheap auto flashes (e.g. Vivitar 283s) to be bounced against ceilings,
softboxes and and brollys in situations where a single strobe is
inadequate (e.g. receptions, wide angle shots in large interiors).

Q1: Does anyone here have experience with such a radio-controlled
   flash set-up and would comment on how pratical and useful it is?

B&H sells the "Quantum Slave 4i" set for $300.  I assume this is an
excellent product - but it is not cheap.

On eBay, an outfit know as Joe's Photo Action sells a similar item -
named "GT301-B" - for around $50.  It is probably less well built than
the Quantum, and has a smaller reach (100 ft vd. 350 ft.) - but
appears to be able do the same thing.  The 100 ft reach is adequate
for my needs.

Here is a link to the eBay item:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3860&item=7501143881

I haven't seen a review of this product, nor have I seen it for sale
anywhere else.  I like the low price, but I also know that you usually
get what you pay for.  The huge price differences compared to the
Quantum kit makes me wary.  It may mean that the GT301-B is a bargain,
or it may mean that it is the sort of useless cr*p one can easily pick
up from eBay if one is not careful (i.e. something that does not work
well, is unreliable, awkward to use, or will break easily).

Q2: Does anyone here have experience with this product and can comment
   on its quality and usability?

Q3: Is there a similar product from other sources I should consider?