Thanks for all the tips and links. Will be going over all of them this weekend.
Kind of freaks me out the nothingness of all of this where if something goes wrong, you can lose it all forever.
Yesterday I downloaded Multibit. It works so much better than the wallet I downloaded about 10 months ago. My old wallet took HOURS to synchronize. Multibit took a few seconds.
Dumb newbie question: If I export the privacy key from Multibit, can I use that key with any another wallet that is not the Multibit wallet? I downloaded Multibit on two laptops. Then exported the key from one laptop and used it to access my money on the other one. It worked so that gave me a bit of a sense of security that if my hard drive crashed on one computer I could still get my money using the other one. But still confused. Is the key generated by wallet programs all you need to get your money from any wallet app as long as you have the key written down? If that is the case I feel better but still takes some faith to put any significant amount of cash out there.
Totally understand the concern about putting your faith in an ethereal nothingness used as money. The dirty secret of modern society though, is that nearly all money (and paper assets!) is the same thing... bits in a computer somewhere. Backed up, maybe, but you can do backups too.
Which brings me to the important point of your post: that the private key is the means of accessing your money.
Some wallets are very simple, and don't allow you to import keys (BitcoinSpinner, a slick Android wallet, comes to mind.) But many will, and even if you couldn't get to one, as long as you have the private key, if you *had* to, you could write out a transaction to move your money
by hand and push it to the bitcoin network. It's real, true digital cash.
The downside of course, being that just like cash, you have to secure it yourself. You'll want to make sure you backup your main wallet ASAP!
But... importing your key from one wallet to another like that isn't really recommended. If you spend from one wallet, then later look at the other, you might wonder why THAT wallet's balance looks wrong. It was a good way to prove the concept though. (It's probably a good idea now to either wipe that second wallet, or remove the key you imported from it, to avoid confusion.)
EDIT: Also, in case it wasn't clear, most wallets contain more than one private key, they may have hundreds. Usually when you spend bitcoins, you get change that automatically goes to one of your other address-key pairs. It's not complicated, but does take some learning and some caution if you plan to mess with private keys inside of your wallets.
