I just toss 'em. Maybe I shouldn't but I do.

I was just thinking about this too -- in doing some excavation on my desk, I came across a whole box of checks from an account I closed several years ago in a state I haven't lived in for even longer.

Somewhere I read that tearing paper documents up and then soaking them in water and rolling them into a ball (but not tearing them through the iron gates of life) makes them pretty hard to read, but I don't entirely trust that for bank stuff.

Lifehacker or similar probably has some advice on this somewhere.

Lifehacker was a good suggestion, thanks nonane. Info on how long to keep financial records.
But I've got oodles of unused checkbooks to dead accounts from all the places I've lived. Maybe I'll just have to make an event of it-- tear them out out individually, rip 'em to bits, set em on fire, have some fun. It'll be the new thing in theme parties.

Woah. Just realized that Lifehacker article I linked quotes from a MeFite's blog, jdroth's Get Rich Slowly.

What's so special about checkbooks? I keep them in a junk drawer. Or cabinet. Or box. Or something. Just like everything else.

I keep the check registers- sort of like a journal. The checks I shred. I collect a grocery bag's worth of stuff, and and take it to the shredder's where they charge me $5 for the whole thing.

Take 'em to Circuit City and use the shredders there? :-P

Tear them up by hand, jumble them together, then throw them out in mixed up batches, preferably in used kitty litter. Or liquid leftovers, or something equally gross. Like nonane's suggestion about getting them wet, only more digusting.

People still use chequebooks? People are unable to use matches to burn incriminating no longer needed documents?

Save for seven years, then toss.

I throw 'em in the woodstove, and dump the ashes in the ginormous pothole in my driveway. At least, that's what I'm doing now. Before I had a woodstove I kept them, along with bank statements and other stuff with financial info, until they filled drawers and boxes and nooks and crannies, and then tore up a small fraction of them when the mood hit me, and moved the rest from place to place. Man, am I glad to have something to burn 'em in.

Throwing them out with the kitty litter is a genius suggestion redvixen! Who would dig through that? I don't generally consider myself paranoid but blank checks are basically free money to unscrupulous people. And I prefer not to underestimate the unscrupulous people of the world.