Here are some FREE or really cheap iPad apps that I find useful for school or personal use. I am willing to show you these and others if a group of you want to get together.
ScreenChomp: Whiteboard App by Techsmith (Techsmith makes Camtasia)
EasyBib: Scan a books barcode and get a ready made citation (MLA, Chicago, APA)
TED: From TED.com
PowerTeacher: Should be active next year at BCPS
Educreations: Another Whiteboard App
ShowMe: Another Whiteboard App
daqri: A way to take your class mobile using QR codes.
Flipboard and Zite: Cool news apps
Keynote Remote: Once we get Macs you can control your presentation from your iPad or iPhone
RedLaser: QR and Barcode Reader
Smart Office: Create word docs from your iPad