If you're only using the palm for datalogging, it would be a waste to get an M500. The color 505 is a waste too. If you plan to use it for work and other things, then I'd go for it. Would you be getting the 500 or the 505 for $250?
The real nice things about the M5xx series are the magnesium case and the rechargable internal batteries. It's small light, so you can actually carry it in your pocket, unlike the M100s. I had a Palm V (predecessor to the M5xx) and I love it, but then it got stolen
The real nice things about the M5xx series are the magnesium case and the rechargable internal batteries. It's small light, so you can actually carry it in your pocket, unlike the M100s. I had a Palm V (predecessor to the M5xx) and I love it, but then it got stolen