I am wondering how to know if the keys for the addresses that are used to receive the "change" from the transactions are included in my backups? I am concerned that even though I may never create "new" addresses by clicking "new address" in the "receive coins" window, that I may end up sending a transaction and having the change go to an address that is not in my backups, and then suffer hardware failure and lost funds as a result.

I am trying to put my mind at ease without having to make new backups after every single transaction, or sweep funds to an address that I know is in the backups after every single transaction. Any information on the matter would be appreciated.

I've participated in these forums some for a while and have commented all around the web in support of Bitcoin. I'm willing to pay a small premium of course as well. I was thinking of giving the virwox thing a try but seems like with limits it will take a while to get $344 worth. (so, like 20 BTC @ USD$17.22)

http://www.youtube.com/watch?v=x8ibOGAebW8

This is promoting a forex site called First National Innovation Brokers (https://www.firstnationalib.com) that I've never heard of that claims to offer standard forex services and also the only forex to accept bitcoin. Thought it was interesting b/c I hadn't seen this before.

http://www.youtube.com/watch?v=SLzqeegRgGg

Note: The entire 2nd half of the video is dedicated to Bitcoin related discussion.

So this just occurred to me. ... Write a unique bitcoin private key (base58 encoded, QR code, or whatever you feel like) on the physical bank notes that come your way. When you pass them on, whoever is the first to actually look at them and do something with the private key will get to claim some bitcoins. It will be an adventure for each and every one of the people who receive them and have any initiative to research about the bitcoin thing. Some of them may receive a note that has already had the coins redeemed -- but going through the process of trying to redeem them in the first place would cause them to go down the rabbit hole.

A variation on this idea would be to run a web service and put short unique urls on the bank notes, where the web service would reveal the private keys and whether/when the bitcoins attached to them had been redeemed. I love this idea so much, I think I'm going to get my big bills converted into fives and write a script or something. I dont have a printer so I'd have to write on the notes by hand, short custom URLs will be easier than long base58 private keys, but doing the full private key info would be a purist approach and wonderfully cryptic to anyone who might receive them.

[EDIT 2012 05 13]

EDIT 2012 05 13: I've released the code on github (see link in recent post). The live system described below is not up and running any longer as i've shut off asterisk since my DIDs and SMS service expired, lol.
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IVR System Introduction:
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This system is still experimental and provides a telephone-banking style interface to an online wallet.
It is running on an Amazon ec2 'small' instance. It uses IPKall DID number with SIP connecting to an Asterisk server running on the instance. Espeak TTS engine is used for the custom voice prompts (forgive the lousy audio quality please). Coding is written in Perl using the AGI interface to asterisk and JSON RPC to interact with the bitcoind that is also running on this system. The SMS gateway is provided by SMSDragon (funded via BTC! awesome!). All accounting/tx/balance information is currently handled only by bitcoind with accounts that map directly to userids. The pin numbers are currently NOT salted/hashed and the wallet.dat file is not encrypted.
That said, this system is functional. I have tested it to send and receive bitcoin into and out of the system as well as between users of the system directly.
I think this tool, or one very much like it, is what is needed to bring bitcoin to the lowest common denominator of voice/sms enabled cell phones throughout the world.
I would like to find out if there is any interest in this type of system. The system in its current state represents three intense days of personal effort to bring together all this work of others into something new and, to me anyway, somewhat exciting.

IVR System Documentation
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Dial Voice # 2538020361 to connect.

When you connect you will be prompted to enter your account number then your pin.
If you dont have an account, press # to create one.

To create your new account you'll just need to enter a pin number then #. The system will read your new syscode ID to you, write it down!

Once you are in your account, you'll have the option to 1) Hear BTC Balance, 2) Send BTC to address book recipient 3) Hear your full form BTC address , 4) Manage your directory of payees, 5) Wait for incoming BTC transactions from other system users and #) to log out of your account.

Listening to your balance you will just hear your current balance.

Listining to your full BTC address will say each digit of your BTC address with nato phonetic alphabet and capitalization info so you can easily write it down, and then will repeat just the characters so you can quickly verify you wrote it down correctly.

Waiting for bitcoin allows you to hear the moment when another user of this system has deposited 6xCONFIRMED bitcoins into your account. You can use these IMMEDIATELY. (Note this loop only reports incoming transactions from other users of the system. For generic btc transactions you'll have to wait for 6 confirmations before you hear you balance has increased.)

The payee directory allows you to add payees in 2 different ways. The first method is to add by syscode aka your userid number in the system. The second way is to receive full form BTC addresses via SMS text message. To complete the SMS process you must set a mobile number onto your account so the system knows from which number to expect SMS messages for you. Once this is complete you can send SMS from that mobile to a virtual mobile number 2064205914. Your text message must contain only the 34 (case-sensitive) characters of the BTC address. The system will find all correctly formed BTC addresses sent via SMS from the mobile number listed on your account and tne you'll be able to send BTC to any of those addresses via regular address book navigation.
Once you have added payees you can list them from the option 3 in the address book manager.

Of course the most important part is being able to send bitcoins, option 2 from the customer menu is how this is done. Simply enter an amount (use * for decimal) and then select an address book recipient. Your transaction will be completed as long as your balance allows it to do so.

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My Favorite Use Case:

Merchant and Customer both have accounts in the system. Customer has some 6x confirmed BTC sitting in his account. Merchant calls and and does the "wait for bitcoin" thing. Meanwhile customer puts in a payment. Merchant hears "You have just receive x.xx bitcoin from acount 55551212" and then completes the transaction. Also because the customer sent 6x confirmed BTC internally to the merchant, the merchant can withdraw that to his exchange account or wherever right away.

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I hope this system can be useful to people who may not have direct access to the internet but have access to a voice+sms mobile phone.