The latest set top boxes could pose a real threat to PCs, with many of the functions but less of the cost.

Sky is to start selling this weekend its personal television recorder (PTR), a hard disk-based device that allows you to treat live TV like video.

Another set top box from British firm Freebox, released this week, offers many of the features of a PC for a tenner up front.

Freebox’s product is not just a digital TV receiver. It can also play DVDs, CDs and MP3s, surf the internet and send emails. All this for a £10 sign up fee, on top of the fees you pay to an ISP and digital TV provider, but it looks like users will have to put up with on-screen adverts in return.

Sky’s PTR, the Tivo, can record up to 40 hours of TV on its hard disk. It can pause and rewind live TV, learn what programs you like and then suggest others based on these preferences.

It could also end the difficulty of programming your video. You record programs by simply selecting them from Tivo’s electronic program guide and pressing the record option.

If the programme time changes, the PTR will still record the correct programme and you can even set up a ‘season ticket’ where it will automatically record all the episodes in a series.

The device costs £399 (incl. VAT) with the Tivo services costing £10 a month or a one off payment of £199.,