Hi, Richard!
When i found in your signature web url www.dynamics... i thought that you can help me, but now i'm not sure because of i see just one info about dynamics in your site related to "Dynamically Resize Images in .Net".
Ok, you right, my previous post looks like not clear, i'll try to describe more detailed:
For sample, we have eCommerce solution which propose to users ability to create on-fly customized sale-items:
1) User can add new Text Fields, flags, DateTime fields, image fields and so on...
2) Based on selected set of fields user creates new type of Item in the system and can in future use this template for creating new sale-items....
For sample, we can create item with just Text, DateTIme and Image for simple items. For more detailed requirements we can add new textField Description, Detailed Description...
All this stuff is processed and creates new database tables, relations, new business types, etc...
Really i don't know how to describe this more clear, i thought dynamic entities is well known Idiom, but in any way i'm agree with you.