Windows Mobile 5 sports many new features and enhancements making it a very worthwhile upgrade. Perhaps the most important feature that everyone will love- from PDA novices to hardcore PDA devotees, is persistent memory. Your data won't be lost if the battery runs completely dry-- a new concept for Pocket PCs, and an old one for MS Smartphones and some Palm brand PDAs such as the LifeDrive and Treo 650. This memory architecture more closely resembles PCs: RAM is used for running programs and not for storage. Your data and all OS files are stored in Flash ROM which doesn't require power to preserve its contents. And just like your computer (and the Palm LifeDrive), Windows Mobile devices can use hard drives as a storage medium. This means we could see a Pocket PC with an embedded MicroDrive (the MicroDrive is a tiny hard drive and it's currently used in the LifeDrive as well as hard disk based MP3 players like the Apple iPod and portable video players). It's less likely we'll see a hard drive in a smartphone since the current trend is to miniaturize phones as much as possible and because hard drives use more power.