1. Visit http://www.vpnbook.com/freevpn
2. Download a Certificate Bundle Under the Free OpenVPN
3. In the downloaded certificate bundle,you'll find .ovpn files
4. Open it in the text editor
5. Copy and send it to your mobile using mail or someother means
6. Paste it in the input box

7. Open the context menu in android Choose "Connect VPN" if it asks username & password Under the Free OpenVPN in http://www.vpnbook.com/freevpn

   or

You can use any other OpenVPN service the thing is you have to paste the contents of ovpn file in input box and Choose Connect VPN

you can try a OpenVPN server's ovpn from http://www.vpngate.net/en/ you don't need to enter username and password and all.

There you go ! VPN connection will get established.

Note:

To clarify any doubts mail me.