CustomFields and other suggestions

Hi,
I am using plaxo online for a quite a while and its very useful service/product.
I think following enhancements will make it more better product
1. Ability to add and name a custom field for example
a user can add "anniversary" field.
2. Subcategories (within categories) for the contacts
3. Ability to add an alert for a field
eg. Alert for "anniversary" field.

Many thanks for such a great service.

Thanks
Sushil