This tip was tested under Debian testing with Vim 7.1 (console version)
To easily swap between different registers in Vim it is convenient to map a sequence to move all in a "circled list". See the following mapping to understand it:
map s :let @x=@" <Return> :let @"=@a <Return> :let @a=@b <Return> :let @b=@x <Return>
Now you can circle between the registers "", "a, "b with s. (:let @a=@b copies register "b to register "a)
This is also usefull if you want to copy between xclipboard and the unnamed standard register of Vim: map s :let @a=@" <Return> :let @"=@+ <Return> :let @+=@a <Return>
To see, what ist changing, you could modify the command above like this: map s :let @x=@" <Return> :let @"=@a <Return> :let @a=@b <Return> :let @b=@x <Return> :reg "ab <Return>
For further Information see: :help let :help reg :help registers