I've quoted a few statistics in my recent talk about Ageing and design at UX Brighton. More details on the UXBrighton 2011 website. You can view my slides on Slideshare.

Sources

"Less than 5% of television characters are portrayed over the age of 60" ~ (Northcott, 1975)

"There are currently 11 million people in the UK between 45 and 60, the so-called 'baby boomers'. They own 70% of the nation's wealth. In 20 years time they could own 85-90% of disposable income in the UK." ~ (Source: Martin Raymond, The Future Laboratory via BBC)

"Over 50s buy 80% of all top of the range cars, 50% of skincare products, 80% of leisure cruises." ~ (Source: Senioragency International via BBC)

"Research shows that 50+ spend more time online than the younger generation; 42 hours per month, where 18-24 year olds spend 37.9 hours." ~ (Flamingo International: Talking 'bout my generationbooklet) also (comScore Media)

"There are equal numbers of age 55+ with iPhones as the 24-30 age bracket."

I took thins quotation directly from the book, but you can see the stats validated by adding up the the 55+s) ~ (Flamingo International: Talking 'bout my generation booklet) also (ComScore Media Jan 2009 - May 2009)

"27% of Americans, age 50+ use social networks" "49% of all adults age 50 and older said they consider themselves extremely or very comfortable using the Internet." ~ (AARP on slideshare)