got this off ebay for a pound so thought i'd share. worked on my e700 first time
Please follow these instructions to UNLOCK your Samsung mobile phones.
Remove Sim card, then replace battery and switch on your mobile
phone.
After switch on the phone (when you will get message Insert Sim)
if
your phone is Samsung D500 / E700 / X600 type in the code #*7337#
if above code doesn't work then please try *#8999*8378#
But if you have Samsung V200 / S300
then type *2767*7822573738#
If you have Samsung S500 / X100 or some older E700’s
then type *2767*688#
if you have Samsung A300 / A800
then type *2767*637#
Now your phone is unlocked (it will reset and should be unlocked for any network.Please remember do not try more than 5 times otherwise your phone will be stuck on that network and you will need to be unlocked with the aid of a cable