I happen to own a blue angel

Siemens SX66. Flashed ROM to WM6. Installed many apps/games. Replace Windows Media Player with TCPMP. DVD ripped video played back smoothly on it. Many graphics intensive games ran just fine. It's a nice PDA, with a phone attached. As a cellphone, it's really too big, too heavy. As PDA, it's still powerful enough compared to today's technology.

If you're so sentimental, maybe you should just keep it as a spare PDA. It only sells for ~60USB on fleabay. Why bother?