I considered offering insurance.  Then I decided it would add unneeded complexity to the code.  It is a mathematical fact that it is NEVER in your best interest to take insurance (over the long run). The only exception is if you are counting cards and the current count indicates that it is favorable to take insurance.  However, since you can't count cards in my game due to the decks being shuffled prior to every hand, then it is NEVER in your best interest to take insurance.  Now some people have told me I should offer insurance for this very reason (because it works in favor of the house).  If this is something people want then I will consider it as a future enhancement.

As for surrender, no, I will not be offering it.  The house edge with the current rules is very very thin (about 0.35%).  Blackjack also has a very high variance.  Because of these things, there are many days when I end up losing significant amounts of bitcoins, and that is why I can not add surrender.

Hand history and win loss ledger will definitely be coming soon as enhancements.

Also, as of now, I have my "crypto-proof" system turned ON.  This system *proves* that every hand you play on http://bitjack21.com is honest.  It proves that:

1.)  The order of the cards was 100% completely random.
2.)  The order of the cards was determined just before the hand started and did not change during the hand.

I have posted an informative page on the site about how the crypto-proof system works, and how you can use it to verify that any given hand was honest:
http://bitjack21.com/cryptoproof

Thanks for playing!
-Mr. Sizlak