Hi, I might have overlooked the blog post and since it's quite old it might be possible that some API's have changed.
i'm not an android developper myself but I found in the doc that the KeyChain API might be the way to go to fulfill the needs. Here is a quick link to the doc for this API http://developer.android.com/reference/ ... Chain.html

I'll be glad to help you to identify the stuff you need to setup a test environment, however since I live in France we might have some trouble scheduling our sessions :-P I'll pm you my gmail address so we can hangout even if I'm at work.

EDIT: I think you'll need to create a new testing app for trying to work with the KeyChain API. You'll then just try to access a webpage protected by SSL certificate authentication. If you've never setup such things or don't want to spend time on it, I can provide you a .p12 key giving you access to a webpage protected on my own webserver.
Anyway, I suggest you to try this way of securing access to your services this is easier than having to use a VPN.
Check your PM i'll give you my gmail, add me, we'll be able to chat.