I like the look of http://manageyourcellar.com/winecellar/do/Welcome

There is a lot of functionality to manage you cellar, such as:
Wines in Cellar
Ready to Drink
Wines on Order
Wines Consumed
Wish List
Recommended
Cellar Book
Cellar Statistics
Best Wine Values
Add Wine
Quick Entry
Cellar Import
Cellar Export
Find Business

You can also view the cellars of other users:
View Other Cellars
Create Group
Tasting Tools
Tasting Reports

As published on their Website these are the top 10 reasons for using manage your cellar:
10. this will help you find what you have in your cellar;
9. this will identify which wines you should drink soon;
8. this will allow you to update your inventory in only a few clicks;
7. this will help you keep track of your pending orders;
6. this will show you what other wine lovers think about a wine, not only professional critics;
5. this will help you keep a balanced cellar;
4. this will allow you to recommend your favorite wines to your friends;
3. this will allow you to record your tasting sessions;
2. this will help you learn more about wine and wine regions;
1. this is free and fun to use!

Manage your cellar can be found on Facebook at:
http://www.facebook.com/apps/application.php?id=28775248698

I hope this proves a suitable choice for you Rob.