That's not ping. G1 is always connected to the internet as soon as it is turned on, that's why.
You can however change the APN to prevent internet access, there is an application that helps you do that or you can do it manually.
if we get data charges or something like that for being in NZ? or if there is anyway around it?
You can simply NOT input the APN setting for your sim card, that way your phone can never get into the internet via 3G/GPRS.
i.e. you get internet only by wifi.
Basically.. do you have any other abnormal charges apart from your calls,texts and normal data usage?
If you are NOT using the default US T-mobile G1 firmware, you won't get any surprise.
Myfaves, inside the T-mobile firmware is known to continually sent sms message back home. There is another cnet story on that.
Btw, I do have a G1 for sale if you are interested. (e-mail me directly for this.)
