I usually buy a newer used laptop once every year or so, alternating between the big one and the little one. I budget about $300 (thankyou, Linux!) for each increment, with each being a little faster then the last, and get a very satisfying sense of progress.
When run, Unison will by default copy files that have changed only on one machine to the other machine, and present a list of files that have changed on both machines for resolution (this list can be very, very short if you only use one machine between syncs, which I recommend). For my stuff (in Unix lingo, my "home" directory) a sync usually takes less then five minutes. Sometimes a lot less.
Unison runs on pretty much all Unix/Linux flavors, Windows, and Macs, so it is also very easy to move from one TYPE of machine to another. (I used to move between Linux and NetBSD, for instance.)
Of course, to test a TCP port, most have probably seen telnet in action:
Telnet, however, only talks TCP. To test a UDP port use netcat:
This displays the Unix time in seconds:
$ date +%s
This converts time in seconds 1190000000 to a readable date/time:
$ date -d @1190000000
Bandwidth across the Great Firewall sucks. That means that downloading an ISO can take hours, even a whole day, if you are pulling it from another country.
Thank you 163.com:
For instance, go here to grab your preferred version of Ubuntu Precise: