Jailbreakers get nervous going anywhere near their Settings app when there is an iOS update that will block their jailbreak exploit. The free Cydia tweak ResetAllKiller aims to give jailbreakers a little peace of mind by disabling the "reset all" buttons in the Reset panel. It may be a little paranoid, but it's always better to be safe than sorry.
ResetAllKiller is free in the BigBoss repo. It's compatible with iOS 4 and 5.
Another simple Cydia tweak released today turns your tweet mode keyboard into a normal keyboard by eliminating the "@" and "#" next to the space bar. NoTweetKeyBoard is available in all languages for free in the BigBoss repo. There are no options to configure, and it requires iOS 5 or higher to download.