I agree completely with the other two comments. This is a truly excellent little device. Small enough to fit in any pocket, yet contains the contents of a book to big for any bag!
I am currently undertaking an MA and the way defining words is so easy to go about, not only does your vocabulary increase, but your understanding of the work increases too.
I do not know how I could live without this now, £60 may seem like a lot, but it is an investment in your future, don't delay buying this!
Here are a few of the features worth praising:
1) Large screen, easy to read long definitions.
2) quick view, allows you to preview all of the definitions available
3) Super jump, jumps to any word within the definition
4) ITS THE FULL OED AND THESAURUS IN A DEVICE THAT FITS IN YOUR PALM!!!!!
4) No need to exit the current definition to search again, simply start typing an it starts a new search.
5) When typing a word it automatically brings up a list of words that begin with the letters you have typed.
Seriously worth the money, you will not be disappointed!