Distinctive features: Sub-Shrub; Flowers and berries are in clusters at the ends of the branches. Fruit smaller.
Similar species: Large Cranberry (Vaccinium macrocarpon) - larger overall: berries are bigger, leaves are larger.
Highbush Cranberry (Viburnum trilobum) - similar in name only. A large shrub.
Notes: Cranberry are actually tiny shrubs, although most people probably wouldn't think of them as such. They grow in bogs.
The main way to tell Large Cranberry and Small Cranberry apart is by the size of the berries.