@bitcoindude & acesun
Thanks for the support!

@enmaku

I agree with you that this solution would be the most cost effective and ubiquitous, but we haven't really considered mag-stripe cards yet, and the reason is (other than I know very little about them:) ) that we want to provide a certain level of security. With mag-stripes the problem is that they could be cloned, and then easily brute-forced to reveal the private key. With a normal card in this situation you could call your bank and declare the card invalid before most of the damage is done, but with bitcoins that option doesn't exist. Of course I strongly support the development of mag-stripe bitcoin cards if there are people willing to use it, it's just that I would like for us to focus first on smartcard based cards because they provide a higher level of security. My suggestion is to prioritize development in this order:

1. Smartcard Bitcoin card
2. Custom hardware with keypad and display Bitcoin card
3. Mag-Stripe Bitcoin card

If we can gather enough people and resources to develop all of three of these options in parallel, excellent!

Again, I must say, that I'm not an expert in this area, and if my assumptions are wrong, please correct me, I would also like to receive continued input from the community during the development of the project. The project is still in it's early beginnings, but already people are starting to participate, and I am really happy about that.