What data structure would be the least painful DataTable replacement?

Question

I'm storing a lot of sorted ~10 row 2 column/key value pairs in ASP.NET cache-- they're the data for dropdownlists. Right now they are all DataTables, which isn't very space efficient (the rule of thumb is 10x increase in size when data is strored in a dataset).

Old Code

DataTable table = dataAccess.GetDataTable();
dropDownList.DataSource = table;

Hoped for new Code

Unknown data = dataAccess.GetSomethingMoreSpaceEfficient();
dropDownList.DataSource = data;

What pre-existing datastructures are similar enough to DataTable that would minimize code breakage and reduce the serialized size when stored in ASP.NET cache?

Answer 1

A Key/Value pair or a Dictionary would be more efficient.

Rick Strahl has a nice example http://www.west-wind.com/Weblog/posts/32508.aspx

Answer 2

Write data to an XML file,based on Session ID, then bind dropdownlists to the XMLDataSource