If you are again in Sydney International and looking for a place to hang pre-flight there are a few relaxed places that you can recharge your laptop or mobile phone with at a nice comfy table, get a decent coffee and enjoy free wi-fi. If on Air NZ and near Gates H, try Dankst Street Depot. Sit on the banquette side as there are wall sockets for power.
If you are near the A-C check in counters (United in the afternoons) Montreux Jazz Cafe (prolific for it's exclusive vintage Montreux Jazz Festival footage in Switzerland on big screens) also has free wi-fi, places to charge, and have a full menu. These are both pre-customs.
After Customs, Bambini Wine Room, again, sit in the banquettes (which have built in speakers for an atmosphere inside an atmosphere and a bit of a nice surprise) is an elegant refuge -- the seats are red and and not easy to miss). As a rediculously frequent flyer, I feel airport lounges are over-rated (crappy food, no service once you are beyond check-point charlie, and no real vibe.) There are a few nice alternatives in Sydney International Airport these days.
Hope this helps!