Just did a 2 week photo expedition in Bonaire in August for http://MarineBio.org, after much research and trial and error here's what worked great for us (three photographer/divers, three different cameras, 3-5 shore/boat dives/day, 1700 photos taken):
Max high-speed CF cards for all cameras (128-512MB multiple cards/camera) - usually used one max card per camera per day.
Rechargeable batteries for the cameras - longer life ones made a big difference. Main downside we found out to cheap digital cameras is short battery lives and having to use external rechargeable batteries... internal rechargeable battery-packs are a must.
1 Winbook - http://www.winbook.com/ - 512mb RAM, 60GB HD and CD-burner (CDs are cheap and burn fast)...
End of night we would download each cameras photos to the laptop, review them in full glory and discuss them which helped us plan..., clear the cards and recharge the cameras for the next day. This stage took most of the guesswork out of it and was the highlight of our trip.
End of trip we burned all photos to CDs as backup in case laptop was stolen or lost....
Back in the office, used laptop to transfer all photos to multiple systems for post-processing, worked like a charm. Hope that helps.