I made the mistake of registering for 18 credits (the maximum) this semester, and ended up dropping two math classes because the workload was just too much. I have an urge to take as many classes as I can possibly handle, and it's difficult to keep it under control. Everything just sounds so interesting. In the Spring, I'm limiting myself to part-time status, no more than three classes. Since I tend to work nearly full-time hours during the semester, even part-time coursework can be difficult.
I'm also in the process of applying to graduate schools and fellowships. I applied for the EPA STAR fellowship last week. Right now I'm taking a break from my NSF GRFP application. One nice thing about the NSF GRFP is the two page limit; I'm able to use my five page STAR application as a starting point and cut things down. Trimming an essay is a lot easier than trying to expand it.
Graduate schools are something I'll consider when I have more time. I'm applying to Ph.D. programs in Ecology, and I'm lucky to have several very interesting options, any of which I'd be happy with.
I have so many low-priority projects and ideas on the shelf right now (including tending to the neglected Scotch programming language.) I look forward to having some time to finally get to some of them.