I have two free invites for the OnePlus One. Below are the links:
Please do not click on the links if you do not want to actually buy the phone, because the invites are then reserved and cannot be used by others.
For a review of the phone see Review of the OnePlus One Smartphone.
Addendum 22-Mar-2015: Both invites unfortunately expired. So people clicked on it without actually wanting to buy a phone.