I hate flying with kneeboards! The most annoying invention they just get in the way (but they ar useful!)
I have an A5 Pooleys one which is excellent for storing bits and pieces in to take flying.
I only take it when im going navving and i only wear it if theres a lot of info to take note of or if its a complicated route PLOG wise. If it's not such a challenging route i just shove it down the side of my seat with my map and look at it when i need to.
Like ASI I always remove mine when im in circuit for TO and landings. However i will rcommend the one i have purely cos its got some good points:
POOLEYS CB8
Got a flight planner to write on in chinagraph
A5 sized clear plastic sheets to stick things in (I have a UK freq. chart and crosswind stuff in them)
Flight levels reminder
Morse code
And some RT bits
Clip for PLOG/Checklist/landing fees and holder for pens
(or i just use my PAX as my holder!!
)