Have you considered the additional air conditioning load during summer?

Is there some way to download this video?  My downloader plugin cannot see the file.

That link works without complaint, thanks.

And even clients that do not generate get a vote, by simply refusing to propagate rejected blocks to their peers.  Much of the network wouldn't even see those modified blocks.

I can't watch it, what format is it in?

Yes, this would work, because an honest client will not propagate an invalid transaction.  But if a smartphone had Internet access, what advantage does an entirely independent lightweight client have over a lightweight client that uses a trusted full client back at the office?  I can't imagine a situation that such a client, for the purpose of accepting payments, would be useful.

Well, it can be enough, depending on how much you trust the counter-party.  However, the normal situation of a lightweight client sending to a full client (i.e. a customer inside a brick&mortar shop) mitigates the double spend risks by limiting the window of time that can be done into miliseconds, because the full client can not only check the transaction's validity but also scan the live transaction queue for transaction that use the same inputs.  But this trick functionally requires a full client with continuous Internet access.

I've been thinking about this further, and I think that a lightweight client (such as would be found on a smartphone) would be one geared toward spending coins rather than receiving and verifying transactions.  That said, a lightweight client, or any client, that was disconnected from the Internet could still check that a transaction was valid by pulling the relevant block headers and merkle trees from the sending client via the same connection that the transaction itself was transmitted across.  Granted, this isn't safe, as it would be possible to spoof, but it certainly wouldn't be an easy thing to do.  Even if both clients were lightweight, the sending client would need to have at least a skeleton copy of the blocks that confirm his own balance.

This, of course, could only tell you that the coins were once owned by the sender, within a reasonable doubt; but not if the transaction is actually valid, as there still seems to be no way to check for a prior spend without scanning all the transactions in blocks that have occurred since.  Such a transaction could still be accepted with the risks.

Well, after you send him the link, he will have been right all along!

Which is why I mentioned an RFID chip as well, which could contain the address that the private key (keypair) hidden inside refers to.  So anyone with an RFID reader could check the address against a blockchain to see if the address still had the coins.

Bitcoin use in an other-than-first-world nation?  Unpossible!

Let this thread be an object lesson to those detractors who claim that Bitcoin can't work in such places; not only do we have Chinese nationals on this forum using Bitcoin, but we now have a real communist! 

Relatively speaking, this is questionable.  Warren Buffet has been quoted as saying that he pays less in federal income taxes than his own secretary.  The point he was trying to make was that the tax code is so complicated that one needs a professional in order to utilize it to one's full advantage, which he can afford and his secretary cannot.

Sounds like a portable POS system, wherein the light client is only used to accept payments, not send them.  Under what conditions would such a crippled client be useful?  You could do exactly the same thing using a remote client, as long as you had real time access to the Internet. 

This goes both ways.  When I was a newbie here, I chose to sit back a read for a while before posting anything, and once I did post it wasn't "is Bitcoin a scam"?  That's comparable to seeing a hot chick in a bar and opening with the pickup line, "I guess you don't put out?".  It's pretty much certain to attract an impolite response.

Wait, are you in Cuba?

Yes, it does look crazy until you understand what the client is actually doing.  Please ignore all of the frustrated 'oldies', but honestly you should have tried to answer your own questions before posting this.  We see this kind of thing every week, and it gets old.

That said, "generating" or "mining" doesn't create money, it is a continuous attempt to solve a proof-of-work compuational problem before anyone else does in order to be the first user to verify the next block in the blockchain.  The blocks contain transaction records, and the blockchain is a huge ledger of all the transactions that have occured between cryptographic accounts, ever.  If your computer is the first to solve a block, and that is accepted as a fact by the network, then you are rewarded for your success with 50 newly issued bitcoins.  In 2013, this block reward drops to 25, and continues to half every four years so that the total number of bitcoins in circulation approaches 21 million.  This proof-of-work combined with a massive, collective and distributed ledger is how Bitcoin can be both distributed without any single point of failure and still prevent double spending of digital funds.

"Is Bitcoin a scam?"

Yes.  So send me all your bitcoins, and you may leave unharmed.

There are some singular miners that you can't undercut.  I don't really understand why I have to keep pointing this out, but much mining occurs in the tiny efficienty type flats of young gaming geeks.  Who live in tiny flats with only electro-resistive heating, and would buy an high end graphics card anyway, most of whom already had one before learning anything about Bitcoin.  This may not be your situation, but there are certainly people who do live in such a situation, and there is no professional mining setup that can drive these guys out of the mining business.  I'd have thought that the market experiences with GNU/Linux and other open source software would have long proven that for-profit companies cannot compete with geeks who don't expect to make a profit.

And when the heat demand for those guys drops off, then the heat demand for their peers in the Southern Hemisphere will go up.

Yes, I have.  Considered getting a set put on my roof.  With government subsidies and a purchasing contract from an Ohio power company, ROI was just over 7 years.  Without the subsidies, ROI would have exceeded the average life expectancy of the panels themselves.  Of course, I wasn't considering them for their investment value, but more for their ability to limit my own family's 'detrimental reliance' on the electric grid.

Plastic casino chip like tokens would work well too, and could use RFID tags inbedded into the plastic to hold the public key.  And even the private key could be micro-etched onto a thin piece of metal imbedded into the plastic, so that the holder of the plastic token could tear it apart to get at the private key.