UPDATE: Thanks to all of you for your suggestions! I've decided, as many of you pointed out, that writing is the best use of my time right now, so that's what I'll be concentrating on for the rest of the summer. First, because if I do decide to leave then more pubs will make me more marketable (and if I stay, it will help my tenure case). Second, I realized yesterday that it's much easier for me to get the tasks that the side project requires---writing scripts, analyzing data---done while teaching, so I'm more likely to make better progress on that during the term than I am on writing during the term. So the plan is to get one conference paper done and ready to submit, along with at least a very rough draft of the journal paper (which will mainly entail cutting and pasting pieces of conference papers together), by the end of the month. We'll see how it goes!
On Sunday nights, Mr. Jane and I have this ritual where we ask each other what our plans are, work-wise, for the week. Usually, I have a ready answer for the question, because usually I'm in the middle of something. But this time, I didn't have an answer. I've just finished writing up something I've been working on for a while, and the "problem" (it's a good problem to have!) is that now I have three or four different directions in which I can go. All of the options are equally promising/intriguing, and I don't have a clear vision as to which one I should tackle first. I'm hoping that blogging about it will bring some clarity.
One possibility is writing up another conference paper, or two, on results that at most will require 1-2 additional short experiments or analyses. The ideas for the papers came up as I was writing up the last conference paper. There are things that were left out of the paper for space reasons and for topical reasons that I think can be turned into 1 or 2 additional conference papers rather easily (and I think I've found appropriate venues for both). Pros: More publications, more lines on the CV, potentially. Cons: the summer's ending quickly; should I instead be spending my time doing experiments and collecting data? (i.e., is writing the best use of my limited time?)
Another possibility also involves writing: I definitely have enough material and results for a journal paper, so I could spend some time getting a draft done and possibly submitted by the end of the summer. Pros: Big publication points for journal articles--I'm doing well in that category but could always use more. Plus there is an increasing amount of interest in my work, so strike while the iron is hot, as they say. Cons: see above.
The third possibility is to spend more time on this little side project I started earlier this summer, which at some point will play a much bigger role in my work but for now is more exploratory in nature. It might lead to a paper, but it's not guaranteed. But it definitely needs to be done at some point. Pros: Finishing this will clarify where I go next with a crucial part of my research. Plus, it's been on my mind for a while, so finishing it will be psychologically freeing. Cons: The payoff is not immediate; this is definitely longer-term work.
So that's my current dilemma. I realize that I can work on a subset of these simultaneously, but for my own sanity I need to feel like one of these is *the* number one priority. Otherwise, I'll just flit from task to task and not accomplish anything. What to do??