  It has been over ten years since Kane's influential proposal for a
silicon-based nuclear spin quantum computer using phosphorous donors. Since
then, silicon-based architectures have been refined as the experimental
challenges associated with the original proposal have become better understood,
while simultaneously a number of powerful and generic models for quantum
computation have emerged. Here, I discuss how the cluster state or "one-way"
model for quantum computing might be advantageously applied to donors in
silicon, with the potential to substantially reduce the practical requirements
of a successful implementation. The essence of the scheme is to use the
electron spin associated with a donor to weave an entangled network between 31P
donor nuclear spins. This resource has been shown to have exceptional coherence
times and supports universal quantum computation through local measurements on
the nuclear spins. Some of the key ingredients, such as global spin
manipulation, have been robustly established, while others, such as single spin
measurement, have seen much progress in recent years. A key challenge will be
the demonstration of electron transfer between donors that preserves spin
coherence.
