ereader: to read various textbooks, documents, articles, web content, etc that I need for both work and grad school. Just last night I was working on some work I brought home and was using the iPad as a second monitor to display documents I was working out of, while working on an excel sheet on my macbook pro.
I also was able to get some reading for school done at the tire shop saturday while getting my tires rotated and balanced.
desktop virtualizer: Can access my work and home desktops via the iPad. The files I was working with last night were stored on my office network, and was able to access them via the citrix app.
I also plug my Macbook Pro into my home theater system at home, and the iPad works really well as a desktop virtualizer/remote for the macbook.
These are the two main functions of my iPad right now, and they both go a long way to make life easier. It has effectively replaced the need for me having to carry a bag full of documents for work, AND a separate bag for my textbooks and documents for grad school. This is huge.
There is a little investment of time to get documents loaded to the iPad, but even if I forget to sync something, between desktop virtualization and utilization of my drop box app, everything I need can be accessed via the iPad on the go.