It appears that US President Barack Obama’s job description now includes signing digital autographs on an iPad. It’s the second time this year that he’s using his finger to sign a tablet, as required by a fan standing in a hallway, at the Lisbon Summit 2010. The first time it happened in the US and now it’s Europe’s turn.

Obama is becoming a pro at signing these devices and we’re curious if he’ll ever switch to leaving a mark on other slates. Notion Ink Adam? Dell’s new Streak? Samsung Galaxy S? What do you say?