You realise that there is one tuner in the TV so you can only record what the TV is showing. Most if not all USB flash (stick) drives will be rejected by the TV because of the data transfer rates i.e. they will be too slow, so your best bet would be to buy a portable USB 2.0 HDD (hard disk drive), powered by the TV, i.e. you will not need to connect the drive to the mains.
These vary in price depending on various factors; manufacturers, quality and the size of the HDD. In my experience a 1hr recording in SD, i.e. standard definition or Freeview is about 660MB, whereas a 1hr recording in HD, i.e. high definition or Freeview HD is about 2GB. So the capacity of the HDD will depend on how many recordings you think you will permanently store on it. If you are just recording a few programmes/films, watching and then deleting, just a small capacity drive will suffice.
Here's an example to illustrate what I mean, and this is a highly rated 320GB or 500GB Toshiba for £41:
http://www.amazon.co.uk/Toshiba-PX16...9663049&sr=1-4
