Microsoft MVP Chris De Herrera has posted one of the largest collection of Windows Mobile Registry settings, hacks, tweaks and customizations, accumulated over the years, for the benefit of Windows Mobile Pocket PC and Smartphone community.

These settings are organized as follows:

Registry Calendar
Registry Input
Registry Messaging - Inbox
Registry Network
Registry Pocket Internet Explorer
Registry Storage
Registry System
Registry User Interface

Click here to visit the Wiki on PocketPCFaq.com.

Remember that Microsoft, OEMs and mobile carriers do not support or recommend editing the device registry.