Correction: a block can currently contain 1MB of data. Originally, there was no limit, but at some point the 1MB limit was added to prevent DOS attacks. It was never intended to be permanent and can be increased or removed entirely if necessary (I think Gavin said the limit would be raised once pruning is implemented).

You can't. The message isn't in the transaction, it's on blockchain.info.

Thank you!

I doubt it, and not just because actually installing the card is a prerequisite to playing games on it.

This is not true in most countries.

It looks like a Sapphire X1550.

EDIT: Actually, it might be an X1600 Pro, which I think is exactly the same card but with the RV530 GPU instead of the RV515. They're identical except for shader performance.

You're missing the fact that an AGP card does not even come close to fitting in a PCI-E slot. Square pegs don't go in round holes. I thought they taught that in kindergarten?

True. But most people's prices are far higher than the market will allow, so for all intents and purposes, these people are incorruptible. At least until inflation hits and market prices increase to the level of these formerly incorruptible people's "asking price", as it were, at which point they'll suddenly start killing each other over the last can of soup... Best not to think about that.

The same way as if you had published your bank account number on your site for the purpose of people sending money to it. Your site has no way of knowing if anyone has sent money to that bank account. However, your bank will know, and you can get the transaction details from your bank. Likewise, your site will not know if you have received bitcoins, but your Bitcoin wallet will, and it will provide the transaction details.

Implying A actually can connect directly to C, which is not always (or even usually) the case. A and C might only be online at different times; C might be a hidden service and A can't use Tor; an evil government firewall might block connections between A and C; or any number of other scenarios may prevent A and C from connecting directly. It is simply not true that any node can always connect to any other node at any time.

Nothing in your post is even remotely true. Therefore, it is false. If you have any reason for believing anything in your post to be true, please provide such reasons.

Many (most?) of these are likely to be spammers whose posts have been deleted.

False.

You should realise that binary options are not true options. With a true option, you have the option of paying the strike price and getting your coins at any time. With a binary option, you never pay the strike price and instead the cost of the option is entirely in the premium, which is therefore much greater for binary options. You're risking a lot more money with binary options, especially if the bitcoin price at expiration is very close to the strike price.

Sure it is. See my signature, for example. Is there a specific problem you're experiencing?

You should also have the Bitcoin address in plain text on the website, for the benefit of people who don't have a Bitcoin client installed and are therefore unable to use the link directly.

You'd add another image. Put it near the donation button. Or make it part of the same image. Either way works.

The public key is irrelevant and unnecessary for this operation. Do nothing with it.

Do especially nothing with it. Private = don't put it on your website.

But they're not his bitcoins. He sold them. He wants to buy them back at a guaranteed price in the future. Hence a call option is the way to go.

No, a collar is where you hold the asset, but don't make or lose money if the price changes, which isn't what the OP wants. Though either strategy requires an options exchange, and there isn't one for bitcoins as far as I know.

Explain how. They only do leveraged trading as far as I can tell, not options.

A futures contract can't do what you want. With a futures contract, you pay for the bitcoins upfront, and get the bitcoins sometime in the future, thus you can't invest your money elsewhere in the meantime (which I assume is the reason you're not simply holding your bitcoins for a month).

What you want is a call option, where you pay a small premium upfront, then pay the full (locked-in) price (called the strike price) when you want to receive the bitcoins. If you don't pay the strike price by the expiration date (which you won't if the bitcoin price has fallen, since you can get the coins cheaper by buying them directly), you don't get the coins and you lose the premium you already paid. Thus, the premium is the cost of this "insurance".

Unfortunately, I don't know of any exchanges that actually offer options trading (someone please correct me if there are).

I smell an X-Y problem. Why do you want to prove someone owns an address? If you think you need to, you're probably doing something wrong.

Pay attention. Biquadratic equations can have up to four solutions. This particular one does, in fact, have four solutions. An answer which gives only one solution is therefore wrong. Now quit giving wrong answers and go back to school.

Wrong. Remember, biquadratic equations may have as many as four solutions.

Since it's a biquadratic equation, we can make it easier by letting z be x^2, so we've got a simple quadratic equation. Simply find the roots of the quadratic equation 1z^2-37z=-36:
  Add 36 to both sides:
  1z^2-37z+36 = 0
  Find the discriminant d = 37^2-4*1*36 = 1225
  Then solve for z: z = (-(-37)+d^(1/2))/(2*1)
  z+ = (37+35)/2  z- = (37-35)/2
  z+ = 36  z- = 1
Since z = x^2, the solutions to the original biquadratic equation are simply the square roots of z:
x++ = 6
x+- = -6
x-+ = 1
x-- = -1

So the four solutions are 6, -6, 1, and -1.