Windows/Mac/Linux: The latest Beta update for Google Chrome does away with the need for clever bookmarklets by automatically dropping down a translation bar when you're browsing another language. It also adds whitelist-type controls over Flash, Java and other browser content.
The video up top demonstrates Chrome's translation bar in practice. It's worth noting that if you don't want Chrome to offer a translation bar for certain foreign languages (those different from the language you set in the preferences), your best bet is to add that language to your list in Chrome's settings — there doesn't seem to be a way to turn it off entirely.
Here's another Google video detailing the content controls:
Development channel users already have these functions, Beta users should get them with their next update at browser launch, and stable users, Google says these features should arrive in the coming weeks. Want to jump ahead to beta or dev? Use the channel changer.
A polyglot Google Chrome beta, with new privacy features [Google Chrome Blog]