Joe Buggy, an Irish genealogist/blogger and author of the book Finding Your Irish Ancestors in New York City, and Shane Wilson, a genealogist and blogger in Dublin, have collaborated to create a database of online Irish directories.

As Buggy states on his website, city directories are a valuable genealogical resource in the United States. Who knew that directories in various formats have been published in Ireland since the mid-18th century? Many have come online, but until now it's been difficult to use them for research because they're spread over a large number of websites. The Buggy/Wilson database of 550 free, subscription and fee-paying sites is located on Wilson's website: http://www.swilson.info/dirdb.php

Their database is likely more helpful for researching ancestors who lived in cities such as Dublin, Belfast, Cork and Limerick, but it's certainly worth making a few queries.