Although shopping isn’t a huge activity here, Mackinac Island [1] does present a few unique browsing options. The Island Scrimshander (906/847-3792, www.scrimshanders.com [2], 9 a.m.–4 p.m. daily May–Oct.), for instance, offers amazing engraved trinkets.
You should also check out La Galerie (906/847-6311, 9 a.m.–4 p.m. daily May–Oct.), with its line of Pandora Jewelry and Christopher Radko Ornaments.
Links:
[1] http://www.moon.com/destinations/michigan/northeast-michigan/mackinac-island
[2] http://www.scrimshanders.com