It would be really nice if the search function (Ctrl+f) displayed a list of occurrences in snippets of their context. Also I would be nice to highlight all occurrences visible in the page, not just the selected one (which could be selected with a darker or brighter tone). The way Evince do it is a good example.
You should vote there: Bug 377487 :)
Until that is implemented, you can use the search box in the Thumbnails side panel.
*** This bug has been marked as a duplicate of bug 377487 ***
Thanks! Sorry for the duplicate, I did do a quick search for this topic but it slipped away in front of my eyes XD.