I would go with a picture comment, try and be original and dont just be like every other guy who is going "Your hot." You want her to see it and then reply back by commenting a picture of yours or just plain commenting you back and whatnot.
Once she comments back you can initiate a conversation, and once it starts flowing maybe say "I think Aim would make this easier, (screename here), or something like that and if she im's you your already sitting pretty.
Then off aim you can number close in no time and text/call and start making some plans.
Just remember if she doesn't comment you back, I wouldn't try commenting her again or anything cause you don't want to seem like a creeper.
Hope this helps a bit.
