I'm having the same problem. I've tried a lot of different things to solve it, but to no avail: reinstalling Chrome, pulling up Chrome's task manager ("view hidden pages") when it happens (no obvious culprit), playing around with Flash (about: plugins), etc.
I can go for several days sometimes where this problem doesn't occur, but it always comes back. It happens sometimes when I first open Chrome. It happens sometimes when I open the next of a number of open tabs. I haven't been able to determine a pattern. If anything, it seems to happen most often with Google's own sites, but it's not limited to them (maybe it's just I go to Google sites a lot). It also happened with the SRWare Iron browser, which is similar to Chrome.
I try other browsers, but I go back to Chrome. I like it and want to use it, but this "page has become unresponsive" routine is getting very old.