I've done this trick a few times without even realizing how easy it was. First you pick a girl, chat her up, compliment her and then the tricky part, ask if you guys can take a picture with either of your phones. If it's on her phone you ask her to text the picture to you or if it's your phone you can tell her you'll send her the picture through text. Either way you'll have each other's numbers and a picture of each other to show your boys. The rest is up to you and your text game. Goodluck and let me know how it goes!