need a simple post navigation

hi!

i need the code to a simple post navigation (browse via next and previous) and i am using a category-based setting.

it should be like that and work on home, category.php and single.php.
<< post-n post-4 post-3 post-2 post-1 >>

the arrows should not disapear but be greyed out (other class or image or something like that)
sounds easy but there was no snippet out there;-)

thanks for help