I don't know where you are but NSW have as association for gifted and talented children (just google it) which offers advice and support for parents as well as advocacy and runs their own programs in the afternoon and on weekends.
I can absolutely attest for how fantastic the NSWAGTC is. There is other services in other states, as well as an Australian association, but NSWAGTC is by far the most organised service in the country. People in SEQLD become members and travel across the border to tweed to participate - the service is simply that much better.

Now, my kids school does have Opportunity Classes. Its a wonderful school - but the OC doesnt start until year 5, and its not helpful as two of my kids have already been bored out of school by kindy. Yes - painting and colouring in is fun - but boooooooooooring. They shot through the reading levels in the first half of the year, and then stagnated - which is where the problem of ignoring giftedness starts. Lyta used to get so bored of the standard work that when she finished and had to "sit and wait" she got up and went wandering through the school visiting her siblings in the middle of class! The teacher never even noticed her leave..

Instead the school does now have PLPs for every student. Both my kids are Visual-Spatial, so that changes how we approach their learning. This is where while I can see Muppity's point, I am going to have to disagree. If they are not taking into account the different ways that children learn - then some children are not learning. I certainly understand schools have finite funding and are doing what they can - but just like medicine - that's no reason for them not to grow, change and become a better service to all students - not just the average. You dont go to a doctor with lung cancer and walk away with amoxycillian because on average, they mostly see people with flu's. You get care tailored to your needs. It may take time, but children deserve the same in an educational setting.