The Apple rumor that keeps on giving -- the touchscreen iMac -- has just been given another shot of monger juice. DigiTimes (who else) cites industry sources who claim again that Sintek Photonics is shipping Apple touchpanels to sample for use in a future 20-plus-inch iMac. Specifically, the panels are of the projected capacitance type (same as iPhone/iPod touch/iPad) and integrate the touch sensor with the glass cover for reduced thickness and weight while exhibiting "good" viewing angles and brightness. While the image above,