Here's a nice cheap mesh for flat shoes. Transparency included so you can shape them as needed and the transparency is posted below the screenshot. Both shoes have the same map, but you can skin them separately so that you can make the shoes different from each other if you like.

This item is meant for derivation purposes only. Don't buy it unless you actually want the unmatched shoes in the pic below.

Please remember to set your derived item to non-derivable.

1-10-09 update: If you find you end up having an odd problem of your derived shoes not showing up in the client when it shows up just fine in the previewer, then you need to go back to an old version of the previewer. Turns out the current version of the previewer doesn't always save the .cfl files correctly.