Agent 18 has introduced its new EcoShield+ case for the iPhone 4. Agent 18 claims at least one recycled plastic bottle is used to create each eco-friendly case, which also features an integrated stand, a sliding headphone jack door, full protection for the Dock Connector port when the stand is closed, a rubber over-mold for added grip and button protection, open access to all other controls and the camera, and a removable bottom half for easy docking.…