I want to

Ultimate Guide to Cataloging Software

The Online Education Blog has a really good article on library cataloging software. Richard Hemby has looked at a wide variety of products and identified 4 in particular:

Delicious Library 2 for the Mac
GCStar collections management software
LibraryThing
MediaMan

Richard does also do a great job of tabulating data on a total of 42 products, so if you're looking to create your own catalogues, this is a helpful and informative article to read.

BeepMyStuff

BeepMyStuff.com makes it easy for you to create an online library of all your DVDs, Blu-Ray Movies, CDs, Video Games and Books. Using your webcam you beep barcodes and build up your online library. It's that easy!.

Collection Database Software

Link: Collection Database Software for  CDs, DVDs, books, games, etc... Commercial products, at £24.95 each. Not tried them, but they look good.

GuruLib Home Library

Link: GuruLib Home Library. GuruLib helps to organize your books, DVDs, music CDs, games and software using a book shelf metaphor.

lib.rario.us

Link: lib.rario.us. Catalogue your books, videos DVDs, music, games, whatever!

LibraryThing

Link: LibraryThing. Free for the first 200 books $10 after that for a year, $25 for life