I now have three methods of getting around Freiburg. I have my student train ticket, my bicycle, and my roller blades. These all overlap somewhat, but I have them all, and getting rid of one of them seems dumb since keeping them doesn't cost me anything.
It certainly makes sense to have the train ticket. I crunched the numbers, and as long as I take one round-trip trip every six days or more often, the ticket pays for itself. So if I take the train to and from church, for example, I'm almost there. It also rains a lot here, and I don't really like getting wet.
The bicycle was a gift from my cousin. It's great because it frees me from the schedule and route of public transportation. Plus, it's knee-strengthening exercise!
The rollerblades are the silly overlap, but I bought them before I knew that my cousin was going to give me a bicycle. It's probably too late to return them, so I'll just use them sometimes. Maybe I can bring them back to the US with me, who knows? They weren't that expensive and it does seem convenient that I can stick them in my backpack and carry them along with me in a way I can't with a bicycle.
Now I just need to buy a bike lock and turn the pedals around so it's rideable, and then I can go anywhere I want, whenever I want!