I have an hp49g+ graphing calculator. I call it My Intended. Unfortunately, I have not yet read the manual because it is on CD-ROM, it would cost $63 to print it. However, I am planning to read most of it soon.

As you probably already know, the hp49g+ is superior to the TI-89 in every way except for the screen resolution and the available games. If you like games, get an 89. Otherwise, ditch TI.

I have written a short tutorial with tips on how to use an SD card with Linux.

http://www.hpcalc.org is the best place to download hp calculator programs, although Dr. Wolfgang Rautenberg has an awesome collection of utilities and other programs at his website.