I do sometimes leave my computer running, due to the constant download of software, games, or videos. This is on my old comp though, since I'm still waiting for my hard drive in the mail. I probably don't want to leave my new comp on though, just afraid maybe hackers, or purhaps it getting to hot. I dunno, I just looked on my AIM and this one guy's had his comp on for I think it's 9 days.