Print, Audio, or eBooks?

I do a lot of "reading" via audio books in the car, as I commute to work. I've noticed that I enjoy some books more in audio, and sometimes I just enjoy the reader. I've loved some audio books read by their authors, especially memoirs. Sometimes, I check out the print book as well, to clarify parts that I didn't understand in audio. I haven't used a Kindle, but I occasionally use eReader on my Treo, to read in the dark and on hiking trips.
This leads me to Ann Kirschner's article in "The Chronicle Review", Reading Dickens Four Ways. Ann read Charles Dickens' Little Dorrit in every format, switching back and forth to compare the experiences (and other readers' reactions). Her conclusions? Everyone has a preferred format, and there are advantages to each. No surprise there! In the end, it doesn't matter which format you prefer, because the interactive experience of reading itself will never die. Ann summed it up beautifully:

It is the sustained and individual encounter with ideas and stories that is so bewitching. If new formats allow us to have more of those, let us welcome and learn from them.