With an extra battery, we had about three hours' talk time. Most of us made one call home during the trip, mainly to let loved ones know we were okay, and the phone also came in handy when confirming float plane pick-ups. With the accompanying pager, we were also able to receive very brief e-mails although we couldn't send any. We kept the phone turned off most of the time, but it was good to know the emergency contact was available if we needed it. We used them to hook flashlights up in our tent, loose gear to barrels and backpacks while portaging, zippers together on luggage, even a small thermometer to the zipper of my jacket.
Possibilities are endless.
More hand cream. Mittens or other warm gloves. Fleece jacket with a water resistant layer on top. Garbage bags, for spreading out on the tent floor on particularly damp or muddy days. A copy of R.M. Patterson's The Dangerous River .