We have prototyped a "spreadsheet component repository" Web site, from which users can copy "components" into their own Excel or Google spreadsheets. Components are collections of cells containing formulae: in real life, they would do useful calculations that many practitioners find hard to program, and would be rigorously tested and documented. Crucially, the user can tell the repository which cells in their spreadsheet to use for a componen's inputs and outputs. The repository will then reshape the component to fit. A single component can therefore be used in many different sizes and shapes of spreadsheet. We hope to set up a spreadsheet equivalent of the high-quality numerical subroutine libraries that revolutionised scientific computing, but where instead of subroutines, the library contains such components.