Griffin's first leather case for the iPod touch is Elan Convertible ($30), a black flip-open design with a removable, two-position belt clip. Designed to be worn either horizontally or vertically at belt level, Elan Convertible is based heavily on the same-named iPhone case, and opens to reveal one hole for the iPod touch's screen and Home button, and another two for the screen's brightness sensor and cosmetic parity. Bottom holes permit Dock Connector…