Maintaining a online relationship involves time and effort from both parties. Whether it is family, friends or a romantic relationship, there are lots of tools to help you keep in touch and share what is happening in your lives -- even if you are far away.
Consider setting up a time to connect on a regular basis. That way you will both look forward to it. Your best bet is to schedule a talk at least once a week. Less frequent connects can be appropriate for staying in touch in some cases but if you want more than a superficial relationship you need to share what is going on in your daily lives. If you are in a committed relationship you may want to connect every day.
Choose the tools you will use. For conversations, consider skype, messenger services such as MSN, AOL and Yahoo. For sharing photos and generally "keeping up" with friends consider social networking sites like Facebook.
Make communication with one another a important event, one you will both look forward to doing. If one person loses interest then it's easy to lose contact.