Remove base path from path saved to the database

Is it possible to remove the base path from the path which is saved to the database? Hard coding the base path causes headaches when moving from dev to production etc. When saving urls we should use the same format as used by the core file module with no base path set as the base path can change. To get the full path we can just wrap the saved database path in the url function.

I haven't played a lot with CCK as documentation is lacking (seriously lacking) but I have attached a patch to the imceimage_field funtion. It works for my needs but probably needs refining as it doesn't take into consideration the absolute url setting in imce, also I haven't had chance to do any proper testing yet other than does it work for the particular user case I need.