I have no affiliation with Cellartracker other than as a satisfied
consumer. I saw Eric LeVine's posts of various fora as he started this
as a (geekish) hobby. Now he's trying to make a go of it as a business.
Registration is free, but eventually it will move towards a paid model.
Currently he takes shareware donations, and one has to be a donor to
take advantage of a few features (bulk import, winebid valuations,
etc).

I had registered earlier, but while his method is much simpler than
entering into Excel or Access, it was still daunting to enter my wines
(over 500 separate bottlings). But he recently developed a bulk import
feature, and I was able to transfer my entire Access base. It still
took a few hours to "map" my wines so they were standardized with other
entries , but I really felt that was worth it. I consider my $40
donation well spent. His premade reports, purchase records for
prearrival wines, views at opinions of drinking windows, and easy
sorting made this far outdo my Access database. And it's easy to export
as an Excel webquery, so if one decides to stop using Cellartracker
all of your info is saved. Strongly recommended if one needs an
inventory program .
Cellartracker.com