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, extracted from an Apple patent, gives us a clue as to how a touchscreen iMac might be used, we remain unconvinced of its advantages (drawing stylus, anyone?). Then again, we're sure Apple has lots of whacky products in house for R&D so why not one more.