Konsole can copy with ctrl + shift + c, and paste with ctrl + shift + v. My right click context menu on Konsole 2.7.4, KDE 4.7.4, Kubuntu 11.10, tells me these keyboard shortcuts.
Edit: There is actually a secondary buffer. Selected text is
automatically added to this buffer, and middle click automatically
pastes it. ctrl + shift + insert will also paste from this buffer.
This can be changed under Settings > Configure Shortcuts > Paste
Selection. ctrl + insert defaults to an alternate for normal copy, and
shift + insert defaults to an alternate for normal paste.