renewing NC driver's license by mail--any experience?

Has anyone done this? I can't find any details on how you go about renewing your driver's license by mail (on the basis of being 'temporarily' non-resident, eg as a student). I don't want my US license to expire, for sentimental and practical reasons...

You might try to find out how on www.state.nc.us [nofollow] .  works for any state by putting in the two character state abbreviation.

i understand about keeping US driving licence.  i use it for renting cars, internal US flight ID, etc.  also, if i ever moved back to the US, it'll be much easier. 

http://www.dmv.org/nc-north-carolina/renew-license.php

looks like the only way to renew is in person (unless you're residing out of the state- not sure how they determine that- and a renewel my post has to be changed when you move back to state)