The Irish Genealogical Research Society has launched an online names index to its annual journal, The Irish Genealogist. It runs to a quarter of a million names and it's free to search.
First published in 1937, The Irish Genealogist has allowed IGRS members to share the results of their research. This has resulted in many thousands of genealogy related articles, family histories and transcriptions of unusual records and sources. Typically, members have submitted information from newspapers, parish registers, family bibles, genealogies, voters lists, pedigrees, membership rolls, deeds, marriage settlements, census substitutes, land and tenure surveys, marriage license bonds, courts records, wills and much more besides.
The index covers the years 1937 to 2001 and will shortly be extended to 2012, creating a database of enormous potential for all Irish genealogists. You can access it at the Society's website, IrishAncestors.ie.