Lambda the Ultimate

Hello. I've been lurking here for a while, but this is my first post. It's a request for advice that I hope more experienced PL scholars might be able to provide.

I'm an undergraduate student of computer science, about to enter my final year. This means I'll soon be required to begin work on a senior thesis. I'm pretty sure that I want to do something related to programming languages; I've always been fascinated by them, and greatly enjoyed the two courses on PL theory and implementation which my school offers.

My problem is that I don't know how to go about finding something to work on. Specifically, a research-ish problem related to programming languages that can feasibly be solved by an undergraduate spending about 20 hours per week on it for six months.

I like the idea of designing a language, and have a few vague ideas of how I might go about doing it, but I'm not sure what actual problem I'd be solving. I wouldn't be averse to a PL-related project that didn't involve designing a language.

So how might one find something to research that's the right level and scope for a senior thesis?

Thank you in advance.