Should It Bulge Like That?

I noticed today that my laptop battery is bulging ominously, and no longer fits properly into the machine (I took it out to get a better look at it and eventually gave up trying to get it back in). Fortunately, I am currently on vacation, and happen to be staying directly upstairs from a Mac shop where I can get it serviced. I've actually been looking into buying a new machine anyway, but I'd rather not do it right this second...

Anyway, it still runs if it's plugged in, but I'd rather not do it too much so I'm not going to be online a great deal for a little bit, I guess...