Although Apple today said it would void the warranty on iPhones damaged by the unlock process (or subsequent iPhone updates), users may be in luck with a new re-locking process outlined by one reader (but not yet tested by MacNN). The unlock hacks are not undone by a full software store; the re-lock process is still in flux and comes with the appropriate warnings to users until finalized, allows users to restore their phone, so Apple’s forthcoming update — due later this week — does not render it inoperable.
It is believed the above proceedure will relock your iPhone and prevent it from being made permanently unusable by the upcoming firmware update. There is no gaurantee [sic], however, and I take no responsibility for your iPhone if the above procedures do not work for you and your iPhone gets hosed."
MacNN | Relocking your iPhone, modding the kybd