If anyone is still interested I poked at this long enough to finally get it let me sync my sony clie handhelds without being root. This might break something else but I haven't had any problems yet, your mileage may vary.
Add this rule to a file in /etc/udev/rules.d that is numbered lower than what in there already. I used 05-local.rules as the file name, I already had it to control several usb hard disks that I swap around.
KERNEL=="ttyUSB[13579]", SUBSYSTEMS=="usb", ATTRS{product}=="Palm Handheld", SYMLINK+="pilot", GROUP="users", OPTIONS+="last_rule"
Adding the last_rule option is what made it all work. There is something down stream that is changing the owner and group of /dev/pilot -> /dev/ttyUSB1 -> tts/USB1 to root. I never did find where it was happening.
Also setting the group to users is probably not the most secure thing to do either so you might want to think about that.
If you want to change the rule around to catch different palm devices this command will give you the information about what is hooked to ttyUSB1. Run it after you hit sync on the palm or ttyUSB1 won't exist yet.
udevinfo -a -p $(udevinfo -q path -n /dev/ttyUSB1)