I noticed a few of the 2006 thrus used Treo devices this year. One couple used it for emails (in place of Pocketmail), phone AND a camera (and their pictures look really nice). The weight of the Treo is listed as 6.4 ounces. Of course there is always the issue of recharging, so one would have to either carry a recharger (unspecified additional weight) or bounce it ahead -- but this isn't any different than it would be for a cell phone.
Anyone considering this to shave some pack weight?