Getting Rid of My Schoolbag?

Basically I'm on the prowl for a device which will let me go without my schoolbag. Since I'm not familiar with PDAs and SmartPhones, I was hoping you guys could point me in the right direction. The features I'm looking for are:

-The standard Clock, Calendar, Alarm Clock, Notes and so forth
-Basic word processing app
-Handwriting recognition or some other very easy way to write massive amounts of text quickly, for effective note-taking
-The functionality of a FULL Graphical Display Calculator (i.e. TI-89 or better); is there some aftermarket app?
-Wireless Internet for browsing and email;
-Music Player supporting WMA playback
-12GB or more of storage space
-Fits in my pocket

Nice Additions (not necessary though):

-Screen about the size of the iPod Touch would be nice
-A USB port for the use of a memory stick (would lower the needed onboard memory quite a bit, so long as it's easy to transfer stuff back and forth)
-Ability to use After-market software and/or OSes (I don't mind messing with software a bit to get the features I want)
-Phone (then I wouldn't have to carry a separate one in my pocket)
-Skype with a headset would be nice when in range of WLAN
-GPS (completely optional)

And the whole thing should preferably be around, or less than $600-$700, if it's a lot less, all the better. Now I'm not even sure if such a device exists, but that's why I'm here!

Thanks Ahead!
-Arminius

P.S. - The bold to provide an quick overview, and for those that can't be bothered to read the whole thing