I'm a librarian who loves anime, manga, and reading a wide variety of genres.
I should have gotten a CueCat ages ago.
On the plus side, I've had plenty of time over the past two and a half years to get a feel for how LibraryThing works and how I'd like to use the collections, tags, and other ways of recording info. It made figuring out what info I wanted to add in batch a snap.
I spent this evening working on a couple smaller book storage areas in my apartment. Just in those areas, I was able to discover two accidental duplicate purchases and one volume I had already reviewed in the past. I also learned that older Tokyopop volumes have crappy back-of-the-book barcodes - every single one of them brings up Tokyo Mew Mew Volume 1 instead of whatever the volume actually is. Fortunately, the barcodes inside the volumes were better.
I still have a long way to go before I'm done, but it'll be interesting to see how many more duplicates I find. After that, I'm going to try to figure out how many incomplete manga series I own, so I can decide which ones to offload and which ones to add to my "fill in the gaps" shopping list.