I understand the responses and even agree on a certain level. But we still live in an external world and shrek619 is looking for an answer accordingly. SO.... YES, it is important!
Girls are still attracted to the outward appearance...if we weren't the commercialized world wouldn't be making billions and spending billions on packaging and marketing things, people and products. Looks are an initial attraction and often a guy/gal is flattered to be with someone that they think are outwardly beautiful. But if the girl has any depth (not a gold digger or simply out for looks to impress others), she's going to want more and looks will not matter for long....character, stability, and security will rule the relationship.
Wait! There's more: I've seen what "mainstream" considers an unattractive guy get the "hot girl" because he took the time to learn how a 'girl' is wired. We are emotional creations and beyond looks, we feel comfortable/attracted and open around someone we think "gets us" mentally. There are a few programs that teach this almost like a 'science' and I watched it from a woman's perspective and had to admit it was spot on. I consider myself intelligent and attractive and want someone pleasing to look at, but after learning this stuff, I realized women will reshape a guy's looks in her own mind to match how she feels about him. His long nose becomes "character", his beady eyes seem....i don't know...cute somehow. He don't have abs, he's got a plump tummy that she likes to feed. And likewise, when she's felt hurt or violated, even the cutest guy's features become distorted and repulsive. I think you understand what I'm saying.