The only way for me to read backlogs is to just keep them open in tabs, at some point I get frustrated by having 50+ tabs open and just triage, read & discard.
I use instapaper for articles I really want to read. The tilt to scroll is amazing. It might be my favorite way to read.
I use Camino so it's happened to me once or twice. I used the history listing to find them again (camino lists both the first and last visits to a given URL, a bunch of URL grouped together with identical last access and first access widely different both from one another and the corresponding last access points to the URLs loaded the last time I launched the browser e.g. after a restart)