So the only other Jasper you can think of is Mr Conran. What about a certain Brummy stand-up comedian?
Elvis Costello was originally Declan Patrick McManus. He probably chose 'Elvis' simply as a way of getting noticed, rather than as any form of tribute. (I've no idea why someone with such a wonderful Irish name should choose 'Costello', which is a Yorkshire nobility name).
Elvis is a Scandinavian name, meaning 'all-wise'.
Keanu is Hawaiian for 'the breeze'. I don't know whether it's common in Hawaii or simply adopted by families on the US mainland.
Harrison simply seems to be using a surname as a forename. In some parts of the UK it's quite common for children to be given their mother's surname as a middle name. While it's less common for a surname to become a first name, it's certainly not unknown.
Dustin comes from the Old German for 'brave warrior'.
Some names which are completely original can, over a period of time, become quite commonplace. 'Wendy', for example, did not exist prior to J M Barrie inventing it for use in 'Peter Pan'. Nobody was called 'Chelsea' until the Clintons decided to give their daughter this name. I also wonder how many children have been named 'Oprah' which, apparently, only came into existence when the registrar mis-heard Ms Winfrey's parents.
I've yet to hear of anyone naming their son after the British actor, Finetime Fontayne!
Chris