[3.0+ & iOS4 COMPATIBLE] Sinful iPhone Language Pack Deleter V.1. UPDATE: HAS BEEN UPDATED FOR iOS4...
Delete those extra language packs to speed up all your iPhone apps. Even the native ones- including Phone, messages, and springboard! Optimizing a Jailbroken iPhone. If you have a jailbroken iPhone, it’s very likely that you installed a lot of apps, tweaks and extensions that are now slowing down your device.
Perhaps you noticed that it’s not as fast as it used to be, applications like Mail take a little longer to start up, you have to respring every 30 minutes to see an increment in speed. You know why? Speed Up Your iPhone/iPod by Removing Launch Daemons. Spirit.