As shown in this video, my computer has been crashing lately. Despite appearances to the contrary, it's unresponsive. It doesn't respond to keystrokes--including the Magic SysRq sequences, assuming I've converted them properly to my keyboard configuration. Sometimes it appears that the mouse will move, but I can't login via SSH. I'm left to reboot by cycling the power, as I can't find any other way out.
I'm a teacher, and this machine usually lives in the staff room. Sometimes, though, I carry it to my classroom for use in class. The crashes tend to happen more frequently upon moving my computer to my classroom, though it's hard to say why. It doesn't necessarily have anything to do with physical movement, but I've only had one crash that did not take place in my classroom--the first.
My machine is a netbook--an HP Mini 110 running Precise. Perhaps also relevant is the fact that lots of programs seem to randomly crash on this machine for no apparent reason, particularly on login.
Edit: At the suggestion of Jorge Castro, I ran a MemTest86+ check on my RAM for about 2 hours and 15 minutes. It found no errors.