iPhone SDK - Display more information about a selected CustomCell (custom UITableViewCell)

Question

I have a CustomCell loaded using:

NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:@"CustomCell" owner:nil options:nil];

I have no problems with the tableview but when I select a row I want display more information on that row(like facebook app)... using the typical "show more".

At the beginning the row show "title" and "description". When I select that row i want to show "title", "description" and a webview... and, of course, make the row bigger to accommodate that objects.

Maybe changing this CustomCell by another bigger CustomCell?

I have no idea where to start.

Thanks. Sorry for my english :S