It's the first of the month which means it's Back Up Your Data Day (although it should be done day-to-day!).
We can also use this day to delete stuff we no longer need and defragment our hard drive(s) to keep our machine lean and clean, if you know what I mean.
Windows guide to defragmenting
Mac users don't have to defragment, apparently.
How To: Back Up All Your Stuff For Free, No Hard Drive Needed
"People don't neglect backing up their computers because it's hard—it isn't, at all. No, people file into the inevitable death march of data loss for one reason: Backing up usually costs money. But it doesn't have to.
When your concerned friends and family insist that you have to back your data up (as anyone who's seen my atrociously beaten-down laptop in the last few months has done to me) they're effectively telling you two things: That backing up your data will save you a massive headache in the future, because more likely the not, your hard drive will fail; and, less bluntly, that you need to buy a hard drive. And who wants to do that? It's hard to lay out the cash for a backup hard drive, since the payoff is uncertain, and (hopefully) far away. It's a good investment—not an easy one.
The good news is, most of us cheapskates can still keep our most important files safe without spending a dime, or wasting more than a few minutes. Here how:
Note: These methods don't give you traditional, full backups—they are ways to keep copies of the files that matter most to you, like your documents, photos, music and videos."
Article in full
A reminder about Matt's simple and effective back-up:
"I have never been able to get the hang of proper backup software and procedures. I always end up getting into a complete pickle about the various full backups, interim backups and how the bloody hell I'd back everything up if my hard-drive became shot with the backup software on it. So these days I just have a complete clone of My Documents on a portable drive and use Microsoft's Synctoy to keep the files up to date."
However I would suggest backing up your entire Documents and Settings folder and not just the My Documents part of it as it which would include emails and favourites/bookmarks. This link has more details.
I asked Lee about the Mac equivalent:
"Things like emails, bookmarks, fonts, templates, RSS feeds, Applescripts - anything used by an application, but not created by it when you hit Save - are kept in your Home folder, in the Library. In Mac speak, that's ~/Library. Apple apps such as Mail, Safari, and iTunes may have their own folders. Non-Apple apps like NetNewsWire, Montage, Final Draft, Scrivener etc, will keep all their stuff in ~/Library/Application Support. The truly paranoid might want to back up their preference files as well. I know I do. These are in ~/Library/Prefences.
For safety's sake, back up the entire Library folder, it's probably only a few hundred megs."
Jason Sutton added:
"Backing up Macs is impossibly easy. Buy an external hard drive and use Time Machine. It's built in to OS X. The best back-ups are the ones you don't have to think about. Brilliant application."
Thank you Matt and Lee and Jason!
Don't delay, do it today. It's Back Up Your Data Day, hooray!