Quote from: kjlimo on May 28, 2013, 03:12:01 AM

A) So you have to put your private key into a website somewhere? That sounds risky

It's all javascript, you can download the page and run it on an offline computer.

Quote from: kjlimo on May 28, 2013, 03:12:01 AM

B) How do I get the private key out of my wallet.dat file anyway?

No idea, I use web wallets.

Quote from: kjlimo on May 28, 2013, 03:12:01 AM

C) Perhaps making a burner blockchain.info account would be a more secure method?

You use the private key of the account you paid with, so you can prove that it's you. Otherwise, I'd be able to request that your units be sent to me

EDIT: Not sure if I misunderstood. You certainly could transfer BTC to a burner blockchain.info account, and pay from that account. The same warning still applies, that you need to have the private key of the address you're paying from.