This is for historians, but appears to be have a lot of capabilities for ethnographers - runs on Win and Mac.
http://chnm.gmu.edu/tools/scribe/
Main Features (from their website)

* Create very long notes (up to 64,000 characters)
* Store published and archival sources (up to 22 types of sources)
* Create, print, and export bibliographies
* Copy footnote and parenthetical references to clipboard in Chicago or MLA format
* Import sources from online catalogs (one at a time only)
* Index note and source cards using a large number of keywords
* Store contact information and notes on authors
* Add extended comments on each card in a separate field
* Search notes and sources by author, title, keyword, note, comments, and other fields
* Perform word search: find and highlight a specific word in the note
* Link sources to notes
* Link sources and notes to images
* Create cross-reference links between cards
* Create an outline and link it to cards
* Create a timeline and link it to cards
* Create a glossary for your project