Please Help! How do I update several rows of data from a Gridview all at once?

Question

Hi,
I have a gridview with text boxes (description fields) and dropdown lists along with bound fields on a Web form. I am using an ObjectDataSource. I am able to easily populate the relavant fields based on my ObjectDataSource. I have a need to be able to permit users to edit the text boxes and change the values in the dropdown list and save all the changes to all rows to the database. I am not using GridView's inbuilt select / update / insert functions in other words, I dont want to save changes per record, instead want to be able to save changes once when the user clicks on a save button.

One thought I had was to create a collection of objects for each row, but that would be an expensive operation with performance issues (if the list is long).

I was wondering if anyone else had faced this issue and how you solved it.

Any help is appreciated.

Regards
Jay