Yes, that is the assumption.  Actually I do a quick depreciation to %65, then linear depreciate to 0%.  

I do consider 2 years to be conservative, but not without a realistic basis.  If a card craps out at month 16, my depreciation cost estimate would instantly become 33% too low.  Also I'm unsure how far factors such as ASIC development and a flood of GPUs into the market following a confidence crash could lower GPU prices.

This.  Ignoring future price speculation, there are really three stages of profitability for each person out there -
1) BTC price is much lower than electricity costs.  Correct move is to sell their hardware.
2) BTC price is above electricity costs, below the level required to pay back the cost of hardware.  Possible moves are to sell hardware, or to mine and hope for the price appreciation.  Correct move is to NOT buy new hardware.
3) BTC is above both electricity and hardware costs.  Correct move is to buy new hardware.

The point is that when price-difficulty relationship reaches stage 2) for a person, they will no longer be considering new hardware purchases - so they will not increase the difficulty.  Stages 1) and 3) are obvious, the difficulty would shrink and grow, respectively.  But 2) is the interesting case, since it could allow us to hit a stable point that is not profitable in the near term.

Power consumption and 2 year linear depreciation on cards, $8.92 / BTC

Pretty sure the invite for free bitcoins isn't for us - he's evangelizing to his friends/family.

I'm guessing he's posting on here more to see if he can get other people on here to do the same thing... maybe?

This is the right idea.  Any chart like this has to be standardized to one particular setup - and therefore a particular hardware depreciation rate and MH/Watt.  Also, as mentioned above, there have been "epochs" where the available processing tech has changed, so back-dating across multiple epochs is tricky.  Within epochs, there is still movement too, just not as jumpy.

Based on context, I think he's referring to a % good/stale shares stat.  So (#good shares) / (#good + #stale shares).  Any better efficiency metric would require you to load the current difficulty...

You've got it right.  Here are a few related threads confirming it :
http://forum.bitcoin.org/index.php?topic=17697.0
https://forum.bitcoin.org/index.php?topic=16845.0

Really easy to check your balance, just go to the main blockexplorer page and put one of the addresses you've generated into it.  It will look up all transactions related to that account.  Try it with your current wallet.

You'd have to be connected to send *from* it.  But to send to it?  Nope.

Also, you can use blockexplorer to check what the block chain thinks your account balance is.  Should be an easy way to check your balance while keeping your wallet "virgin".

That should definitely work.

And there I was, trying to keep it constructive.  It's your loss - there is a lot I could teach you if you weren't so afraid of being wrong that you're not willing to listen.

The AC voltage at the wall doesn't matter, your computer's power supply converts that into lower voltage DC.  As far as I know, a 12V rail supplies a lot of the power to a video card.  So a good graphics card would probably pull over 25Amps at 12V DC.  At the end of the day, that isn't something you need to worry about since computer equipment manufacturers report the maximum Wattage requirements to you.  Those computer parts can then be paired with a power supply which is also simplified to watts in the "big label" literature.  If you're building a computer it is good to know the amperage at each voltage, but it isn't a necessary consideration for this discussion.

Sitting at about 1 hour of logged in time, would like to be allowed into the wider world of forums so that I can report/discuss an error I'm getting using the flexible mining proxy.  More specifically, I'm running a windows machine with VC9 compiled apache 2.2 and PHP5.3.  When I turn error reporting on it shows a a "cannot convert to string" error in the MVC class cdhowie provided with the build.

I've helped out a bit in the newbie forums already.  Thanks for your time.

I was also able to submit the form and 3 forms of proof without problem.  Pretty thorough... wonder to what extent they will be evaluating them by hand.

You may also consider moving off of the VGA port, if possible.  I had some success reducing artifacts by moving to HDMI.

Really?  There will be a 24 hour notice period before MtGox's exchange opens, so everyone should be able to redo their buy/sell orders before trading recommences.  Since the old orders won't be extant, why would there be "cheap coins" available?

I think the current tradehill price is reflective of the current market price if mtgox was still open.

Electricity use is charged in watts (includes the voltage the amps are pushed at), not amps.  You'd be using maybe 650W, or 0.65kWatts per hour.  That's about 468kWhour per month, at 13 cents a watt that would be $60.84 per month.  Probably a conservative guess on the high side.

Bitcoin already has a nice lottery feature built in : solo mining.

Just a quick hello/first post.  Looking forward to seeing where bitcoins go.