Recently I have been using Cellar Tracker, which is an online wine inventory tool.  Overall, I am very pleased with this tool.  One of the best things about this tool is that it is free.  They do however, prominately request donations.  That seems fair though for a rather useful and well written tool.

Some things do not seem to be yet implemented (or at least not entirely) community fetures (public sharing of cellar data), integration into E-Robert Parker and more.  It does however, currently include some level of barcode support; though I have not used that yet.

One improvement I would like to see made is with how storage locations are managed.  I enjoy the freeform nature of the storage locations; however, I would prefer to have an interface just for managing storage locations and place location and bin limits to force accurate inventory records.