synergy: The popular one requires 2 pairs twisted. There was one that hit all 8 wires, but I don't think much became of it.

That sounds like it could be the HP-backed AnyLAN VG (sp??? I actually saw it in the wild once -- a hospital that bought a turn-key lab system based on all-HP hardware). I think it would run on Cat 3 with all 8 wires. Same with 100BaseT T4 media type, I think, designed to re-use existing Cat 3 on 8 wires, but not sure how much it gets implemented in vendor equipment (or for that matter how -- can a port support both T4 and TX??).

Back to my regularly scheduled Triple Americano...