I know that I'm probably the last person in the world to do so, but I've just finished HP7. I bought the complete set of audiobooks of the series, and listened to them all in my car on my way to and from work; it's taken me just under two months to do so

. I think that Stephen Fry, who narrates them, is absolutely wonderful. He has a distinct "voice" for each character - his "Voldemort" voice is particularly good!
I won't give away any spoilers to those who haven't read it yet, but I was just "blown away" by the ending to the series. Absolutely superb. I'm devastated that that's it - no more new HP to look forward to. Is life worth going on with?
If anyone thinks audiobooks aren't worth listening to, this is the series to get in that format. It's great - a real "performance" rather than merely a "reading"! There are two separate versions, the US version, narrated by Jim Dale, and the UK version done, as I say, by Stephen Fry. Personally I think that Mr. Fry is hugely better.