I would be wary of pursuing a Master's degree when you don't have a particular interest or field you want to pursue. Two reasons: avoiding over-specialization, and making good use of your time.

Regarding specialization. Broadly speaking, the (employment) world is oriented around the idea that an undergrad degree is a kind of "proof of principle"-- a general certification that you can slog your way through some problems. Therefore an undergrad degree doesn't necessarily limit what you can do. Nobody is going to say, "You have an undergrad in ECE, so there's no possible way you could work on our chemical engineering problem."

Once you go for a higher degree, though, people start to think of you as that thing. You might very well find somebody saying "You have an MS in computer science, so you're too expensive/too specialized to work on our chemical engineering problem."

Regarding good use of your time. Going for a Master's degree is, generally speaking, a two-year endeavor, plus whatever money invested, which you may have to pay off later-- not to mention the opportunity cost of not earning money during that time. So you need to start thinking in terms of whether the degree is going to prepare you for what you really want to do. You already have the experience of getting out of an undergrad degree and feeling pretty uninspired by what you are now prepared to do. Do you want that to happen to you again when you get out of your MS degree?

An alternate use of those two years might be to work a job-- doesn't have to be in your "chosen" field-- and think about what excites and motivates you. If after that time you have an itch to get a Master's degree in a particular area, then you won't have to post a question to HN to decide whether it makes sense for you.

To make this concrete, I'll offer up my own experience as an example (not to say mine was the best way, but it informs how I think about this question).

I did a co-op program as an undergrad, and learned enough about Electrical/Computer engineering to understand that I could be good at a job in it, and could even take pleasure in the day-to-day aspects of it, but ultimately would feel indifferent to the "big picture" of what I was doing. After graduating, I did a stint in Peace Corps, then came back and worked at a research semiconductor fab for a 3-4 years. During this time, I was noticing how my Peace Corps experience informed my interpretation of things in the fab (for example, I was probably more aware of energy consumption in the plant than others). Finally I went for a Master's degree, with a clear idea what I wanted to do with it.

When I got my MS, I had a few interviews at engineering-consulting type firms, where the general tenor of the questions was "Now you know, we just plug numbers into spreadsheets here, right? We don't have time for any of your fancy-pants simulation and data analysis."

So in my experience, taking a little time after undergrad to figure out what you want to do is a win, while getting a Master's degree starts to make people look at you as specialized in a particular way. I'm sure somebody else had the experience of feeling uncertain, doing a Master's, and loving it so much they chose that as their ultimate field. That's why this is, finally, a personal decision-- so good luck to you.