How can I keep things going with him?

Truth be told, I'm pretty good at seeing the world from a guy's perspective. With that being said, I'm finding myself in a bit of a dilemma and I'm hoping some outsider perspective will help me figure out what the heck to do. Here are the basics:

Just over a week ago, I went out with my girlfriends to a club and ended up dancing with a guy all night. I cabbed back to his house, and was expecting a drunken hookup. We talked a lot and messed around a bit, and when I said I wanted to have sex he stopped me and said he wasn't sure if we should, because he wanted to ask me out on a date. I was thrilled, and we stayed up half the night talking. We tried to have sex a bit later, but he couldn't get it up (not a huge deal in my eyes considering how drunk we were, but I'm sure he wasn't too pleased)

Two nights later, we go out for dinner and he comes back to my house to watch a movie. We mess around a bit more, talk, and attempt sex again. It works - too well perhaps. He finished super quickly (again, not an issue for me. he put the effort in to making sure I was satisfied). We stay up all night talking and having an amazing time. I seriously like this guy.

Here's where my problems begin...

The next morning, I had to pack up and move away! I'm done school for the year, and I'm back in my hometown for the summer. It's only a half day's trip away and we agreed to stay in contact, but at this point I have no idea how much contact is too much. How am I supposed to show him I'm interested without setting aside whole weekends to go visit him, or have him come visit? I'm not worried about appearing clingy or needy, because I'm not. I am worried that because I'm going to be busy this summer and have zero interest in pointless texts back and forth, he's going to lose interest or think I'm less interested than I am.

What I really am hoping to get are some suggestions on how to maintain where we are now/keep things moving when there's this distance between us and we really don't know each other that well. I'm pretty sure that at this point, he's aware that I'm not just looking for sex from him. I had an awesome time on our date and have really enjoyed getting to know him. I really would like to stay in contact this summer; it was such awful timing and he told me he was bummed I had to leave so soon after we'd met, so I have hope. But at the same time, I'm struggling with how to keep things going. I know this was long, but anyone willing to tackle my issue will be very much appreciated!

Did he know you were going to leave before he went on a date with you? Is it possible that that was the reason for him to go on the date (so there wouldn't be anything "serious" coming from it)? Did you discuss with him keeping things alive?

He knew I was leaving, but very shortly after we met he said something like "why do you have to leave so soon?" It did occur to me that he might not want to keep things going once I left (and that's the mindset I held for a long time) but before I left we did discuss keeping in touch. He said something along the lines of worst case scenario, we'd just text every once in a while or only drunk text each other, which seems like a good sign if he wants more than that. I just have no idea how to do it!! He did also mention that he might be in the city I'm in now within the next couple weekends, and mentioned meeting up. I feel like that's a good sign.

The summer is not all that long. My advice is plan a visit of some sort that you can both look forward to, email back and forth, and exchange some texts here and there. If you have something to look forward to, it will help keep you both interested.

Jaime