So my favorite way to identify gifted kids would be to offer kids chances to participate in meaningful learning opportunities well above what is expected for their age level and see who thrives.
The only problem I see in implementation (b/c this happens a lot locally to me) is that, if the majority of the kids who show up/enroll are not gifted, the programming morphs to "looking at bugs" like another mom posted about in her thread about summer camps. Rather than weeding out the kids who aren't a match for the program, the program morphs to be a match for who showed up and becomes less and less of a fit for kids who need and want the meaningful, advanced, deep learning opportunities.
But, that is a different thread -- lol!