Amy had a post the other day explaining about a nifty feature Raverly has added (although she's unsure how long ago). It's a bookmarklet, located on the Pattern section of Ravelry. If you use Firefox or Safari as your browser, you can drag it to your bookmark bar and when you find a pattern on the web, click the "ravel it" bookmarklet and it'll allow you to look up the pattern if it's in the Ravelry database. Amy had a super idea about using the button on your pattern page which will directly link it to your Ravelry page.
You can find the bookmarklet on the bottom of the Pattern page on Ravelry (scroll all the way down).