Regarding all the comments here about dial-up and slow connections whether out of preference or necessity, I can't recommend enough having a slow connection and a data limit for helping you concentrate on the things that are most important to you, but take the most effort to think about or to do. I use a three mobile 3g dongle (UK) and pay £10 a month for 1GB of downloads. I use wget to crawl and download web pages to view offline. I've been doing this for over a year now and it's great for avoiding the huge potential distractions of broadband, torrents for example, being amongst the worst offenders (have you ever downloaded a 100 computer science textbooks and never got round to any of them because you were watching a whole season of star trek: next generation? It's kind of ridiculous.)
