Consumable and monetary gifts are definitely great choices. I also like giving the gift of my time. Before my best gal pal moved across the country, we'd celebrate our birthdays by treating each other to lunch and spending an afternoon doing whatever the birthday girl wanted. Some years that meant helping with some thorough housecleaning, and some years that meant playing board games all day. Whatever the birthday girl wanted to do, the other willingly went along. There were occasional small gifts, but only things we knew for certain would be used and appreciated.
She recently celebrated her first birthday since moving. We had a "phone/internet birthday party." We set aside a few hours, each bought our favorite snack foods, and spent an afternoon talking on the phone, munching on chips, and playing games together online. Not as fun as hanging out with her in person, but it was a decent substitute.
