I have friends in India (indefinitely), Barcelona (recently), and Korea (temporarily) - but lately I'm noticing more and more web applications make it easier and easier for me to stay connected and feel like my friends are part of my life and my day.
I am using Twitter to route text messages to India and receive them back just as quickly. It costs no more than a usual text message.
The other night I used AOL IM to include Bruce in a game of Scategories while he sat at an apartment in Korea. It was rudimentary but it brought him into a game with 6 of his friends back at my apartment on New York.
A few of us used Skype to hold a conference call for the fraternity Housing Corporation while we were in Barcelona talking to undergrads back in Boston.
This isn't even getting into how simple it is to email, facebook, and more. I remember back in high school when a close friend went to France for the summer and it took 3 weeks to get a letter to her - now I communicate with friends in several different ways throughout the day and it's completely seemless.