There are two things I take with me all the time:
- My E-Book Reader
- My Diary / Notebook
I love hardcopy books, more than my e-book reader, but if I travel light, it's my first choice because:
1. I can take as many "books" as I want with me.
2. I improve my English every time I read a book because I can long-press on a word to open a popup with the definition/dictionary.
3. Words I look up are added to the vocabulary builder so I can look them up later.
4. With "Word Wise", I can see simple definitions and synonyms displayed inline above more difficult words while I read.
Just to mention some.
My notebook is with me for my daily notes incl. highlights from reading e-books, which I want to keep track of in two places.