When I first told my girlfriend I loved her, I wrote her a poem. I always say "I love you" when we log off AIM, hang up the phone, or say our goodbyes after a date. Though it gets boring saying the same thing so occasionally I'll spice it up a bit by elaborating, or writing her another poem, or making her a picture. It's not enough to say "I love you", you have to do something really sweet every once in a while, or else it loses meaning.