See this answer for using the SIM as Secure Element https://stackoverflow.com/a/9364030/156477 (Its not scalable solution at present).
This isn't Google's code, and the SEEK API isn't part of Android (out of the box). Have a look at http://code.google.com/p/seek-for-android/wiki/SmartcardAPI. You'll see at the bottom you need to rebuild your own version of the Android OS, and flash it to your device.
I notice you haven't tagged the question with NFC. I wonder, do you really need SmartCard support or do you just need to store data securely? The typical SmartCard use case is to use the phone for payment, or building access - know as NFC Card Emulation mode.