Acai berries come from the acai palm native to south america. It's almost impossible to find the actual berries for sale. You'll have more luck searching online for dried versions or powdered acai. It's benefits are mostly thought to come from it's high anti-oxidant content.
However cinnamon has nearly the highest ORAC rating for antioxidants than anything.
Heres a quick reference to it's nutritional value from wikipedias' page on acai.
<i><u>Most of the research to date on açaí has focused on a particular freeze-dried form referred to as Opti-açaí.[2][3] This powder preparation of freeze-dried açaí fruit pulp and skin was reported to contain (per 100 g of extract) 533.9 calories, 52.2 g carbohydrates, 8.1 g protein, and 32.5 g total fat. The carbohydrate portion included 44.2 g of fiber.[2] The powder was also shown to contain (per 100 g): negligible vitamin C, 260 mg calcium, 4.4 mg iron, and 1002 U vitamin A, as well as aspartic acid and glutamic acid; the amino acid content was 7.59% of total dry weight.</i></u>
And a link to that page if it works. <i>http://en.wikipedia.org/wiki/A%C3%A7a%C3%AD_Palm</i>
Hope this helped.