How about the main differences between E680 and E680i

[davidchen]

Can someone tell me the main differences of developing apps between E680 and E680i?

[rpconnect]

it depends on what environment you want to work with. Opie for example uses a completely different set of qt libs than either the e680 or e680i and will work on both. Java development will also work for both models. If you want to develop using the phone's native qt libs then there are some compatibility issues between the two as the qt libs on the e680 and e680i are not quite the same.