I have just come across this group, Click.  A vocal jazz group out of London.

Click are a six-piece London-based vocal jazz group with a strictly voice-only policy.  They aim to recreate the sounds of big band jazz without instruments.  I hear that they are a fun group to watch and I am not sure that the clip does them justice.  Formed out of the well regarded Oxford Gargoyles they are well worth looking out for if you are in London.

The parent group, the Oxford Gargoyles have released several CDs. Here they are performing “I get a Kick Out of You”. Sinatra it aint, but they would give you a good night out.