For instruction and how-tos, screenshots, etc, I wish to have a payment of 1 BTC sent to an address I give you, but from an untouched generated block, one where the payment address was only used in the generated block and will never be used again, ideally one that generated exactly 50BTC with no earned fees (although this may be hard), and maybe even no transactions (nearly impossible?). It should be sent to me with no transaction fee. This way I get 1 BTC and the change will be 49 BTC. Older generates are better if you have many to choose from, and old will guarantee decent priority with no fee. Do what you want with the 49 BTC, but sending the remainder to a mixer or an exchange's one-time deposit address would be recommended since it may be closely examined by the curious in the future.
1. Identify the address and generate block that meets my needs, let me review and we agree it works (I'll pay 1 BTC first if your rep makes it likely you own the block generate you claim),
2. Export the private key from your wallet
3. Import it into a fresh Bitcoin install with new wallet (different machine or VM),
4. Set transaction fee to 0 in client, (do not send with fee),
5. Verify 50 BTC balance in block are still unspent,
6. Send the address I give 1 BTC, this Bitcoin gets back the change (ideally hit send right after new Bitcoin block)
7. Send the wallet's 49 BTC balance somewhere else in one payment after six or more confirmations.
8. Sometime after you've got your 49 BTC out and I've got the 1 BTC, delete the Bitcoin data directory and/or wallet so addresses don't get accidentally used again.
9. (optional, but if needed to remove any doubt) Delete the generate address from old wallet so it never gets accidentally used.
I can do step 3-8 with your private key, but I don't expect someone to essentially loan me access to their 50BTC for a while. I don't have near that much in BTC right now myself, and don't think I would "buy" a private key that could be remotely zapped either.
If you screw it up majorly sending and the data doesn't fit my purposes, I'll send you back the payment to whatever address you want, maybe to try again if you have more generates. If it's good, you get 2 BTC (or 1 BTC more if prepaid).
I'm not in a huge hurry. It's not a big bounty, however, after making mature example payments to be used for publication, I will later publish details of the addresses and simple payments for the community to be used for learning and screenshots, probably including some private key(s) (although I would put a MtGox sweeper on any private keys disclosed to discourage people from sending more money and causing any confusion). The typical instruction that the payment address may be useful for: "how coins are generated", "how to follow coins on block explorer", "how to import private keys", "see wallet balance (no money needed)"; "watch confirmations and balance as spending blocks are received", "try to double-spend already spent coins", etc.
PS: A possible feature for Bitcoin experimenting useful for more than just me: a 'pause' button on block downloading or a "stop downloading at xxxxxx block" option, while the client otherwise operates normally.