This post like last time, will be over a band I've been listening to for a while now (though I do need to catch up and listen to their newer albums) though their musical style is so distinctive that every time I hear one of their songs I instantly recognize their use of guitars and ....violin, so if you didn't instantly know who it was then you are new and I would like to introduce you to a rock band named Yellowcard and yes, they are a rock band that incorporates a violin into its music and it sounds great. So we're going to follow chronological order (sort of)  and start at their roots and not go straight to Ocean Avenue...yet. Their early work was notably different than any the rest due to their early hardcore punk sound with Ben Dobson's rough vocals compared to later years with Ryan Key's smoother voice that ultimately changed them to their current sound. Though the only major difference between the two eras was the vocals everything else remained somewhat the same minus a slight difference in guitar overdrive and greater violin presence which came to be a sound that could be instantly recognized. I keep addressing the use of a violin in this band not because of the "holy crap a violin in rock" aspect of it, but that it has a role in the sound of the band that rivals the guitars in importance because of the long, almost singing aspect of a violin which is extremely prevalent in many of these songs many of which altogether contradict their pop-punk genre genre label (they don't really adhere one genre and vary their sound) in which they'll utilize acoustic guitars with lyrics that were intended as an attempt to break into country music.
http://www.youtube.com/watch?feature=endscreen&NR=1&v=DFsmjMA0rK4 acoustic guitar use, violin prevalence
http://www.youtube.com/watch?v=L6eXIQ3f8Zw violin presence
http://www.youtube.com/watch?v=aqgxOfmLeU0 heavy country influence,violin prevalence
Compare these two:

http://www.youtube.com/watch?v=szNlPr78P5U early stuff off of Midget Tossing

http://www.youtube.com/watch?v=z5KZnzZZQ-s this is one of their better known songs off of Ocean Avenue

http://www.youtube.com/watch?v=10-mEWsM72Y from newest album Southern Air