I have an iPod (not used) and an iPhone (attached to me) and I was gifted with an iPad (with me most of the time.)
There is an amazing number of apps - I found one that will store knitting patterns and keep track of my rows...and another that is a ruler. I no longer have to carry patterns and tape measures.
And an eating log.
The three I use most are
#1. Cozi. I've got the app on my phone and pad, Tom has it on his iPad. I can put my grocery list on the site from my computer, and anybody with the app can add to it - I access it at the store and if it's not on the list...don't blame me for not buying it!
On Cozi, I also take a few minutes at the start of the week to put my Scripture reading list into a Cozi "to do" list. that way, I can open my
#2 - ESV Study Bible and read anywhere.
#3 - Kindle App. There are WAY too many books that are free, or $.99. And it's way too easy to click on the "buy now" and spend too much on books.
While I'm away from home, I read the kindle app. At home, I mostly read the "hardware" and if it's a book that I'll want to loan or mark up, I get both.
(NOTE: I do have a twitter account that I probably don't use the right way. I twitter what I'm reading, as I read it...keeping my reading list in the sidebar of my blog.)