Getting over the hump
I'd suggest that for those older individuals the reason for ignoring the internet has less to do with difficulty, access or cost, but more to do with lousy website design (the Disabilties Discrimination Act notwithstanding), the physical constraints of using a mouse with arthritic fingers and the poor interfaces for people who have never learned to type or who find it difficult.
After all, it's completely alien to a twenty-something webdesigner to appreciate that double-clicking can take several seconds, or that the wizzy piece of flashy (if not Flash) graphics they were so proud of is utterly irrelevant to someone with poor eyesight.
Also, you have to ask: what precisely, are the advantages of the internet to someone who doesn't surf for porn, who doesn't work in IT or who's friends don't spend all their waking hours tweeting about their last fart? Maybe the elderly aren't missing out so much as have an alternative lifestyle where the internet is just another channel on daytime TV?
So with these high and artificial barriers to adoption and little benefit from it's use, maybe it's not too surprising that a large number of people have neither reason nor incentive to get online. Did I just hear Martha Lane-Fox's head explode?