Don't know much about these books, but they get a good write up on wired… both ePub (Barnes & Noble) and mobi (Kindle) formats.
Here's a short blurb from the wired.com website; "Jonathan Wood’s debut novel, No Hero, introduced the world to Arthur Wallace, the MI37 agent who dared ask: “What Would Kurt Russell Do?” […] Well, today we’re thrilled to be offering digital copies of No Hero and the just-released sequel, Yesterday’s Hero, free for the next week."
I do enjoy a freebie with no strings. The books seem to be decently written - my interest has been piqued after the first few pages.