Here's one of my all-time favorite way to write binary literals in C by abusing define:

    #define HEXIFY(X) 0x##X##LU

    #define B8IFY(Y) (((Y&0x0000000FLU)?1:0)  + \
                     ((Y&0x000000F0LU)?2:0)  + \
                     ((Y&0x00000F00LU)?4:0)  + \
                     ((Y&0x0000F000LU)?8:0)  + \
                     ((Y&0x000F0000LU)?16:0) + \
                     ((Y&0x00F00000LU)?32:0) + \
                     ((Y&0x0F000000LU)?64:0) + \
                     ((Y&0xF0000000LU)?128:0))

    #define B8(Z) ((unsigned char)B8IFY(HEXIFY(Z)))

And now you can write:

    B(01011010)

Etc.

If you like this, see my blog post about bithacks.h:

http://www.catonmat.net/blog/bit-hacks-header-file/