you can use manual profiles to keep track of home made dvds. when you are on the add dvd screen do an add by title and deselect the download profile from invelos check box. then you can manual create the entry and it wont be contributable.

as far as dvds you watched but don't want to buy some people do this. you have 3 options.
1) use the ordered or wishlist tab to track these
2) use tags to mark dvds in your collection as not owned but just seen. you can then use the MyTabs plugin (plugins are not available with more than 50 profiles on the free version) to add your own custom tabs and have these flagged profiles show up on a custom tab called rented or watched (or whatever you want to call it)
*edit*
3) What Gsyren said below

-Agrare

Quoting Agrare:

Quote:
when you are on the add dvd screen do an add by title and deselect the download profile from invelos check box. then you can manual create the entry
-Agrare

Thank you, that worked perfectly  .  Tomorrow I'll play with the suggestions for those I've watched but don't own.