If you use vim then I highly recommend mapping spacebar to page-down and shift-spacebar to page-up. This key is kinda useless otherwise and super-helpful afterwards. It is also the largest key on your keyboard. usability++

    nmap <space> <c-d>
    nmap <s-space> <c-u>
    vmap <space> <c-d>
    vmap <s-space> <c-u>