Lampshaded: "My girlfriend lives in Boston, so I only get to see her a couple times a year...thank God for the Internet!"
Invoked: Alice meets Bob through an online forum.
Defied: Alice and Bob decide that warm, fuzzy feelings to the contrary, an LDR is just too stressful and inconvenient. They decide to be Just Friends.
Deconstructed: The long distance can put strain on the relationship: there's UST and the fact that the other person is missed but not there, and it can lead to cheating...or jealousy and suspicion of cheating.
Reconstructed: Alice and Bob agree to spend time talking to one another and invest in webcams, and they make the most of the time they do get to spend together in person. They also agree to be faithful to one another and stick to that.
Played For Laughs: Bob comes over... And turns out to be a Starfish Alien
Played For Drama: Alice and Bob miss each other so much, and get jealous...the relationship becomes an emotional rollercoaster. Can they overcome their problems? Or will they end up breaking up?