What happens if you meet an amazing girl (or whomever) but the person lives in a different city? Like New York. And you are in Philadelphia. But you want to try to make it work. Oy.
Split in Two
As someone who married a long-distance boyfriend, I'm perhaps uniquely qualified to answer this question. A long distance relationship can get serious quickly because when you are seeing each other, it's for concentrated amounts of time removed from other facets of your life. Or, you can have fun when you're together and not dwell on the other person when you're not. That in-between "let's see how it goes" attitude creates a murkiness unknown to same-city relationships. You can do it, but it means you spend less time being fully present in any given situation than you otherwise might and less time knowing exactly where you stand in the other person's life.
In a recent column about when to say no to a second date  even if the first date was wonderful, long-distance is one of the reasons I cited. It's not just that long distance is a deal breaker, though. Long distance is a deal breaker if neither one of you has the potential to be geographically mobile in the foreseeable future. You don't have to be ready to relocate this month or even this year, but this decade has to be an option.
You say, "make it work," without specifying what "it" is. If it's a short term, romantic out-of-town fling, I'm sure you can make it work. If it's a serious relationship possibly resulting in marriage, you have to be willing to significantly alter your current life in Philadelphia to make that work. That means seeing your local friends less, arranging your schedule around someone else's and giving up some of your own routine and comforts. Those conditions aren't necessarily different than what you have to do in any other relationship, they're just more present and pressing.
For a long distance relationship to be successful, one or both of you has to have a flexible enough schedule that you'll actually be able to spend some real time together. You also have to have a reciprocal willingness to travel, as one person bearing the brunt of the traveling can quickly lead to resentment. If it makes sense for one person to do most of the traveling, discuss early on how to split the transportation costs. I also suggest either setting expectations together or being extremely fluid about your own expectations when it comes to how much to talk on the phone, email and text when you're not together.
When you're getting to know someone primarily through technology and in weekend-long spurts, it's harder to see the full picture of his/her life and ensure that you're getting to know the "real" person. Make sure to meet her friends, learn about her daily routines and see her hang-outs. When she's in Philly, make sure you share those things with her. You have the unique opportunity to self-censor how she gets to know you, but use that responsibly and make sure you're learning what you need to know, too.
Lest I sound entirely discouraging, I'll remind you again that seven years ago, I met the most incredible man who happened to live several stops away on Amtrak's Northeast Corridor. After ten difficult (and exciting, wonderful and romantic!) months traveling between Philadelphia and Boston, I moved here. We got engaged less than a year later. Now there's no question that we know each other's real personalities, routines and friends. As with so much of my dating advice, my recommendation comes down to this: When you know it's right, you have a feeling and go with it. The intricacies of dissecting every interim move become far less important than all those relationships that have ended in the past. When I met my husband, my roommate at the time tried to dissuade me from getting involved. Sometimes you have to know when to take advice and when to leave it.