Last week TiVo and Amazon made public their video download service, which they call Unbox. If you have a TiVo series 2 or 3 machine you can register it with Amazon and then download movies and TV shows, either renting or purchasing the titles.

If you rent the show it goes away after a while. If you purchase it then Amazon notes that fact and allows you to download it any time you want (so that you need not keep it permanently on your TiVo). Downloads take an hour or two even on broadband and you cannot stream the material, but you can start the download from anywhere on the Web so the show could be ready for you by the time you get home if you do it from work, say.

We tried it last night with a movie and found that it worked smoothly. The video quality exceeded the "best" setting on TiVo but fell a tad short of regular DVD: we noticed a couple of stutters or frame drops - not sure whether this was a technological issue or editing to save a few frames here and there.

If you just want to watch a TV show or movie (and don't care about a typical DVD's special features), this is a great service. Costs vary quite a bit for different offerings and rent vs. own, but if you want to try it out sign up soon for $15 worth of trial downloads and see it for yourself. A lot of TV shows cost only $2-3 and buy movies compares to buying DVDs.