I was doing a half marathon. You could totally do one if you wanted to, just work up to it slowly. It seems intimidating, but it's something that's really achievable for most runners, particularly if you just want to run it, not race it.
I have no idea what races I'm going to do next! I think I'm going to stick to shorter races like 5k and 10k this summer and try to work on my speed before I think about the longer distances again.
That, or my husband and I are considering being crazy and signing up for the Goofy challenge at Disney World in January, which means running a half marathon on Saturday then the full marathon on Sunday