In many occasions it would be very useful to have fields that the end user can post to. i.e. Custom Front End Fields.
In the resource manager such front end fields could be used to poll for data through choice fields, users could post comments through the simple or rich text box, websites could be submitted through URL fields, admins could get really creative with the php callback function, etc, etc.
For example, if the RM hosts addons then the admin could add a front end custom field 'website URL' for users to show the website where they have software installed.
There are endless possibilities of how to use this.
In threads, such custom post fields would be useful in a similar way. Addons could make use of custom front end fields in many ways.