For several years, I have managed my book collection using Booxter for the Macintosh. It has been a great program, but there were also a few limitations that bothered me: (1) a lack of more advanced but common fields (such as awards); (2) no custom fields for tracking information not captured by the system; (3) no good way to maintain data integrity; (4) limited export to web features.
Today, I found a great Mac-based book collection software called Bookpedia. I spent 10 minutes reading through it’s feature list and bought the $18 license on the spot. It’s got everything that Booxter has, plus everything that I want that Booxter is missing. You can built customized export templates. It’s even got a feature to assign a book in your collection a unique ID, something very useful if exporting the data and manipulating it programmatically. It’s also got lots of great visual stats. It even has a template for exporting your lists to an iPhone.
Overall, I’m very impressed with it. I’ve imported my Booxter library (which is several months out of date, which is one of the reasons I was looking into this to begin with) and I really like the features.