Probably I am a little bit old-fashioned, but I still use J-Pilot on my PC and my Tungsten T5 and sync them. It mostly serves as a kind of backup so I have my valuable address and datebook data on separate media. So in case my PC gets inaccessible then I have my data on this device at least.
These are the commands I use.
echo 1 > /proc/sys/net/ipv4/ip_forward /usr/bin/dund --listen --channel 1 --pppd /usr/sbin/pppd call dun hciconfig hci0 piscan
debug 115200 noauth nopersist local passive netmask 255.255.255.0 192.168.178.118:192.168.178.119 ms-dns 192.168.178.1