To copy,paste between emacs and other applications....

By default U can't copy from an application say Firefox to emacs...
(a difficult situation for somebody like me who tweak on others code)

Copy pasting from emacs to aother applications are also not supported...

U can get it done by adding just two lines to your .emacs file..
(U can't copy paste it if U R using emacs for editing .emacs file...)

(setq x-select-enable-clipboard t)
(setq interprogram-paste-function
'x-cut-buffer-or-selection-value)

Done...

Now copy something to your clipboard from an application say firefox and
click C-y in emacs it gets copied....

Now do C-k(kill) a line a try C-v in any other application say gedit..it gets
pasted...