Very similar to Jamie Cullum in terms of jazzness, only he plays with an acoustic guitar instead of piano, and is more experimental with his instrument in my opinion. I'm going out tomorrow to buy his latest album "On and Off" after hearing a few tracks earlier.
At the moment my favourite tracks are "Taylor" , "Cookie Jar" , "Traffic In The Sky" , "Flake" ..... the list goes on, too many to mention and they're all really really good songs.
Music you can relax to, similar to Counting Crows in some ways, quite bluesy and jazzy with very distinct vocals. He's done a few songs with Ben Harper so it's worth giving him a mention too, also very talented, although different from Jack.
He isn't very well known, so I guess it makes him that bit more special.
Buy Buy Buy!
Here's a link to a (bad quality) preview of all the tracks on his latest album:
http://www2.hmv.co.uk/hmvweb/display...1;-1&sku=61179