Why Germany wants its 674 tons of gold back
http://www.washingtonpost.com/blogs/wonkblog/wp/2013/01/16/why-germany-wants-its-674-tons-of-gold-back/

Germany Wants Its Gold Back—Should You Worry?
http://www.cnbc.com/id/100382718

Why Germany Wants to See its US Gold
http://www.spiegel.de/international/germany/german-politicians-demand-to-see-gold-in-us-federal-reserve-a-864068.html

Here it is again on TechCrunch:

http://techcrunch.com/2013/04/04/9flats-bitcoin/?hubRefSrc=permalink#lf_comment=67507636

The aforementioned comment on Wired can be found at the bottom of this article:

http://www.wired.co.uk/news/archive/2013-04/3/first-bitcoin-atm

And here's a Reddit thread on the transaction:

http://www.reddit.com/r/Bitcoin/comments/1bpyab/3_btc_transaction_consumes_97288_kb_of_data_why/

I feel "entitled" to email anyone who shares his or her email address with the world. S/he is of course free to ignore my email. We are all equals, my friend.

It was actually to post here so that the entire community could have a definitive answer to this question. Ironically, it was a post of yours that finally convinced me that I had to check with someone who would actually know the correct answer: https://bitcointalk.org/index.php?topic=145437.msg1553996#msg1553996

I had even replied to that comment 5 days ago asking for any further details from you or the community: https://bitcointalk.org/index.php?topic=145437.msg1670599#msg1670599

Sadly, apparently no one here knew the correct answer or could be bothered to share it. I decided to try my best to find out and share the answer so that others could benefit. With the blockchain well over 7.5GB and growing fast, it is important that users know how to copy the blockchain correctly.

Thanks very much for confirming that, Matt!

For 0.8+, you may want to skip at least the deprecated blkxxxx.dat and blkindex.dat files since they are no longer used and are quite large. More on the data directory contents: https://en.bitcoin.it/wiki/Data_directory

Looking for a definitive answer to the safety of long-term storage, I emailed Gavin:

Barring any unusual attacks/bugs, should a paper wallet essentially last indefinitely, enduring hard/soft forks, etc? Or is it conceivable that the coins could become unusable in the normal course of Bitcoins growth?

His reply:

No.

Unable to find a definitive answer to the question of copying the blockchain to another computer, I asked Gavin via email:

In Bitcoin-Qt 0.8+, how can the blockchain be copied from one computer to another? Is it simply a matter of copying the blocks and chainstate directories?

His reply:

Yes

As you type that, the BTC/USD exchange rate is over $84 on Mt.Gox.

Just put the files in the default location:

~/Library/Application Support/Bitcoin

The tilde (~) represents the root directory of your home folder. The full path would look something like:

/Users/username/Library/Application Support/Bitcoin

If you wanted to change the default location, one way would be to use a symlink. I had to do this for the iMovie data directory years ago:

http://tinyapps.org/blog/mac/200805230700_change_imovie_save_directory.html

Thanks very much - just sent an email with my order number.

Hi TangibleCryptography,

Thanks for providing such a well-respected service as well as support here on the forums.

My sell order from last week shows the status as "PAID" and a company check number is listed, but "Mailing Date" and "Tracking" are blank. Are these latter fields simply not being used at the moment?

Thanks, Vladimir. After finding this comparison of ASICs and video cards, I see what you mean:

https://en.bitcoin.it/wiki/Mining_hardware_comparison

EDIT: I'm sure most folks here have seen this, but for others who stumble onto this thread, this is worth reading:

Miner problem: big changes are coming for Bitcoin's working class
http://www.theverge.com/2012/11/16/3649784/bitcoin-mining-asics-block-reward-change

What current or truly-soon-to-be-released hardware would make a good alternative to waiting for ASIC hardware? That is, is there any hobbyist configuration that could come close to rivaling ASIC without an astronomical electric bill?

Thanks for the info, deepceleron. Do you know if it is possible to copy the 0.8 blockchain to a new computer by simply pasting the blocks and chainstate directories? Any further info on whether such a transfer would work cross-platform or not?

Sorry for cross posting - I did not receive a reply to this question here: https://bitcointalk.org/index.php?topic=143220.msg1666681#msg1666681 .

UPDATE: https://bitcointalk.org/index.php?topic=143220.msg1694068#msg1694068

It seems that in 0.8.1 those have been superceded by two new directories: blocks and chainstate. There is a third directory named "database", but I dimly recall that being present in previous versions as well.

As of 3/23/13, those three directories contain about 7.76GB of data, with blocks making up 7.57GB of that total.

Is copying the blockchain to a new machine as simple as pasting one or more of these directories? Is there any reason to keep blk0001.dat, blk0002.dat and blkindex.dat?

Thanks again, theymos!

Speaking of long-term concerns with Bitcoin, have you read this critique?

On the fact that Bitcoin has a Kill Switch; and how to disconnect it.
http://www.loper-os.org/?p=1009

The basic thrust is that a very few individuals own the vast majority of Bitcoins, that they actively conceal this fact through obfuscation, and that they will "kill" Bitcoin at some point by flooding the market. (This last claim strikes me as rather remote - what possible gain could they hope to achieve?)

Thanks for your reply, theymos! I wasn't aware of this eventual pitfall and started digging around. This thread was especially interesting:

How long would it take a large computer to crack a private key?
http://bitcoin.stackexchange.com/questions/2847/how-long-would-it-take-a-large-computer-to-crack-a-private-key

and this link found there:

Why not use larger cipher keys?
http://security.stackexchange.com/questions/25375/why-not-use-larger-cipher-keys/25392

Any thoughts on this comment from http://www.schneier.com/blog/archives/2012/10/analysis_of_how.html#c929588?

Thanks everyone for your replies!

Here's to hoping that we see an Illustrated Guide to Bitcoin from O'Reilly soon! 

If Bitcoins are stored long-term offline or on paper as described in these links:

How to set up a secure offline savings wallet
https://en.bitcoin.it/wiki/How_to_set_up_a_secure_offline_savings_wallet

Paper wallet
https://en.bitcoin.it/wiki/Paper_wallet

Offline USB/CD and Paper Bitcoin Wallets
http://bitcoinmagazine.com/offline-usb-cd-and-paper-bitcoin-wallets/

will they be useable forever, even after the various soft and hard forks we've been hearing about lately? Or is there some chance they could become unusable?

The reason I ask is this: After not firing up Bitcoin-Qt for a year or so, I upgraded to the latest version and had a bit of a scare when it initally reported all of my Bitcoins as unconfirmed:

https://bitcointalk.org/index.php?topic=150802.0

It took a 7GB+ download of the blockchain to restore them to my balance.

Thanks again, mwag and RodeoX!

After catching up, Bitcoin-Qt 0.8.0 showed the correct balance.

What a difference a year makes! The old blockchain (compromised of blk0001.dat and blkindex.dat apparently) was well under 2GB. It looks like Bitcoin-Qt 0.8.0 created a new subdirectory called "blocks" which is full of .dat files exceeding 7GB! No wonder it took so long to catch up. Before too long I'll need a dedicated machine just to host my wallet!

Again, thanks so much for the encouragement to let the upgrade process finish.