While I'm not aware of any textbook apps per se, I do use the iPad for textbook reading. One of my classes uses the connect service from McGraw-Hill and it has its pros and cons.
PROS:
Don't have to carry around 10 pound textbook (although I also used the service on my laptop)
Quick page flipping
CONS:
Can't have book open to a problem we are doing in class and to pages to take notes. You have to constantly switch between apps, something you still have to do on a laptop but is much easier. I'm hoping when the iPad eventually gets os4, multitasking will fix this problem.
(May only apply to online e-Books or services like connect) Sometimes if you change between apps or web pages (for example if I'm doing my homework (which is also part of connect) and I’m flipping between the problems and the book) the page will reload and I'll either loose my place in the book or the answer to the problem)
Other then that, if you still use paper to take notes and the books you need are not online but part of a different app I say go for it! It's a lot of fun to take notes on (or not)
Also it's almost the end of the semester so I don't carry my backpack around anymore, meaning all I bring is my iPad. If you were planning on using the iPad exclusively for eBooks and your laptop for notes that would probably work really well!
