As has been stated the "groove" you play is not the same as the options you have in the "groove". The simple answer is to increase your available musical vocabulary to draw on. Listen to lots of various types of music and listen to the way the notes move within the structure of the song.
Part of the problem you will encounter is not changing the substance of a song for the sake of it, changing it in a way that does not keep it faithful to genre or original intent. And in other ways this is a good thing because it is what you are looking for but a balance has to be found and understood.
In the link is a band who like Dread Zeppelin were highly original verging on near genius for having the ideas in the fist place.
Like Dread Zeppelin Black Sweden have their critics on both sides who hate what they do...i think it is great because it music out of the box.
http://www.youtube.com/watch?v=uD7ZLe5Nauc
and here is some Dred Zep as well..
http://www.youtube.com/watch?v=CZHWy...eature=related