Got to be a Cruzer Blade 16GB flash drive for just over £14.
Also have bought a 750GB External USB Powered HDD.
Not the best price i could get it for, but still reasonable.
The Amazon Kindle 3G... although it's Becky's, I still use it a lot
It's a cracking little ebook reader and far better than I thought it would be. The browser is surprisingly decent and it's really handy for trips when you'd like to read lots of books.