Does any evidence show that Smartphone users have poorer memory? An ages old complaint is that new technology harms memory. Why remember something when you can look it up? 

In a course on Human Memory I distinctly recall an interesting discussion on phones and memory, and an interesting point came up; even though smart phones mean we no longer remember phone numbers as often as we used to we have to remember passwords, userids and other trivial bits of information which keeps our encoding skills sharp. However I don't recall and studies to support this hypothesis.

Are there any recent studies to suggest whether users of portable digital tools like smartphones actually perform worse on any memory-related psychometrics? 

And no I'm not talking about these extremely questionable Cellphones Harm Memory in Mice stories the media has picked up on. I'm not concerned with electromagnetic radiation's effects on the brain, but rather the effect of having easy access to external information.
One relevant study by Sparrow et al. (2011) that came out last year in Science was on the "Google effect": When subjects expected that they'd be able to have later access to information, their memory was poorer for it. We can extrapolate to smartphones -- if individuals know they have information at their fingertips, they don't need to worry so much about retaining that information.


Betsy Sparrow, Jenny Liu, and Daniel M. Wegner (2011) Google Effects on Memory: Cognitive Consequences of Having Information at Our Fingertips Science 1207745 Published online 14 July 2011 [DOI:10.1126/science.1207745] (Free PDF)