The Pew Internet & American Life Project has released its latest research on mobile phone usage in the US, and since it’s free of commercial obligations to promote any particular technology or service, they make useful reading.

Topline findings: 56% of American mobile phone owners access the internet on their devices – this is feature phones as well as smartphones – while 50% send or receive emails, 43% download apps, 31% look for health or medical information online, and 29% do some form of online banking.

All this usage is growing, too: in Pew’s 2009 study, 22% of mobile phone owners were downloading apps, while 25% were accessing the internet.

The report drills down into some useful demographics too: 65% of 18-29 year-olds are downloading apps on their phones, while 53% of 30-49 year-olds are.

An important question is how much further this app percentage can rise. Earlier this month, comScore estimated that 51% of Americans now own smartphones – the key devices for app downloading.

Rough cross-referencing of the comScore and Pew figures indicates that at least 8% of smartphone owners AREN’T downloading apps*, so it’s not a given that buying a smarter handset leads to ‘smarter’ use of its features – something also touched upon by recent research by Asymco into Android engagement.

*The caveat being that we don’t know how many of the 43% of app downloaders in Pew’s study are on feature phones