Organizers behind Office 2.0 Conference have come up with an ingenious, if costly, incentive to drive attendance to their upcoming developer/partner conference. Registered attendees and speakers will receive free 4GB iPhones. Where do I sign up? Well not so fast. A single attendee registration costs $995 through July 31 (that's tomorrow), after which the registration price jumps to $1,495. If you're a developer living in the Bay area, and had already planned to attend O2O, this is a no brainer. However, this conference price (even with iPhone) seems unusually high to me.