Has anyone implemented a sitemap footer in the storefront? This would replace the link to the sitemap, with the top level nav options always visible and then an expand/contract button/link to show the expanded second level of menu options under the top level.

[+]
Top 1 Top 2 Top 3 (always visible)

Top 1A Top2A (no second level)
Top 1B Top2B
Top2C