Most home computers still seem to be configured with one main user account, even when frequently used by several different people. So then they either end up mucking up each other’s files and settings, or resort to careful arrangements of subfolders and multiple profiles in individual apps.

If you’re still doing that, spend some time creating separate accounts and try out Fast User Switching in OS X (which handles it beautifully) or XP/Vista (less robust). Yeah, you then have to log in to take your turn at the computer, and it uses more memory, but it’s usually well worth it to have quick access to your own desktop, files, bookmarks, history, email, wallpaper, etc., and the insinuations of secret porn browsing will subside eventually.